Research Article
Research Article
Et latet et lucet: Discoveries from the Phyletisches Museum amber and copal collection in Jena, Germany
expand article infoBrendon E. Boudinot§|, Bernhard L. Bock§, Michael Weingardt§, Daniel Tröger§, Jan Batelka, Di LI§#, Adrian Richter¤§, Hans Pohl§, Olivia T. D. Moosdorf§|, Kenny Jandausch«§, Jörg U. Hammel», Rolf G. Beutel§
‡ Senckenberg Naturmuseum Frankfurt, Frankfurt, Germany
§ Friedrich-Schiller-Universität Jena, Jena, Germany
| National Museum of Natural History, Smithsonian Institution, Washington, United States of America
¶ Charles University, Praha, Czech Republic
# China Agricultural University, Beijing, China
¤ Okinawa Institute of Science and Technology Graduate University, Onna san, Japan
« Institute for Anatomie I, Jena University Hospital, Jena, Germany
» Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany
Open Access


As the only direct records of the history of evolution, it is critical to determine the geological source of biota-bearing fossils. Through the application of synchrotron-radiation micro-computed tomography (SR-µ-CT), Fourier-transformed infrared-spectroscopy (FT-IR), visual evaluation of ultraviolet fluorescence (UV-VS), radiocarbon dating (14C quantification), and historical sleuthing, we were able to identify and sort 161 (83 Baltic amber, 71 Copal and 7 Kauri gum pieces) individually numbered and largely mislabeled pieces of East African Defaunation resin (~145 years old) and copal (~390 years old), as well as Baltic amber (~35 million years old) from the Phyletisches Museum collection. Based on this collection, we define two new species: ‡Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov. (Psocodea: Amphientomidae, copal) and †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (Coleoptera: Mordellidae, Baltic amber). For selected taxa, we provide systematic reviews of the fossil record, including: Amphientomidae, for which we provide a key to all species of Amphientomum, extant and extinct, and recognize the junior synonymy of Am. ectostriolatum Li, 2002 (an unjustified emendation) under Am. ectostriolate Li, 1999 (syn. nov.); the fossil ant genus †Yantaromyrmex and the clades Dorylinae, Plagiolepidini, Camponotus, Crematogaster, and Pheidole (Formicidae); the Nevrorthidae (Neuroptera); and Doliopygus (Coleoptera: Curculionidae: Platypodinae). We synonymize Palaeoseopsis Enderlein, 1925 with Amphientomum Pictet, 1854, syn. nov. and transfer one species from Amphientomum, forming Lithoseopsis indentatum (Turner, 1975), comb. nov. To prevent the uncritical usage of unidentifiable fossils attributed to Camponotus for macroevolutionary analysis, we transfer 29 species to the form genus †Camponotites Steinbach, 1967, which we consider to be most useful as incertae sedis in the Formicinae. We treat †Ctt. ullrichi (Bachmayer, 1960), comb. nov. as unidentifiable hence invalid stat. nov. We also transfer †Ca. mengei Mayr, 1868 and its junior synonym †Ca. igneus Mayr, 1868 to a new genus, †Eocamponotus Boudinot, gen. nov., which is incertae sedis in the Camponotini. Concluding our revision of Camponotus fossils, we transfer †Ca. palaeopterus (Zhang, 1989) to Liometopum (Dolichoderinae), resulting in †L. palaeopterum comb. nov. and the junior synonymy of †Shanwangella Zhang, 1989, syn. nov. under Liometopum Mayr, 1861. Because the type specimens of the genera †Palaeosminthurus Pierce & Gibron, 1962, stat. rev. and †Pseudocamponotus Carpenter, 1930 are unidentifiable due to poor preservation, we consider these taxa unidentifiable hence invalid stat. nov. To avoid unsupported use of the available fossils names attributed to Crematogaster for divergence dating calibration points, we transfer three species to a new collective taxon that is incertae sedis in Myrmicinae, †Incertogaster Boudinot, gen. nov., forming †In. aurora (LaPolla & Greenwalt, 2015), †In. praecursor (Emery, 1891), comb. nov., and †In. primitiva (Radchenko & Dlussky, 2019), comb. nov. Finally, we transfer †Ph. cordata (Holl, 1829) back to Pheidole, and designate a neotype from our copal collection based on all available evidence. All new species plus the neotype of ‡Ph. cordata are depicted with 3D cybertypes from our µ-CT scan data. We introduce the convention of a double dagger symbol (‡) to indicate fossils in copal or Defaunation resin, as these may yet be extant. To further contextualize our results, we provide a discussion of amber history and classification, as well as the Kleinkuhren locality, to which multiple specimens were attributed. We conclude with conspecti on key biological problems and increasing potential of µ-CT for phylogenetic paleontology.

Key Words

ants, barklice, best practices, digitization, lacewings, micro-computed tomography (µ-CT), morphology, museomics, phenomics, taxonomy

1. Introduction

Et latet et lucet Phaethontide condita gutta, ut videatur apis nectare clusa suo.

“Caught in a[n] [amber tear] drop of Phaethontide a bee is hidden and shines, so that it may be seen that she is buried in her own nectar.”

– (Mart. 4.32), Marcus Valerius Martialis (between 38 and 41 AD – 102 and 104 AD)

The Phyletisches Museum in Jena, Germany, was founded by the famous and notorious zoologist Ernst Haeckel, who laid the foundation stone in 1907 and donated the museum to the University of Jena in 1908. Today, the collection of the Jugendstil or Art Nouveau building contains about 750,000 specimens, of which insects represent approximately two thirds, while the remainder is divided among the other animal classes and phyla, with vertebrates forming a large and valuable proportion. Since its founding, the museum has accumulated material from notable scientific figures, including Haeckel’s successor Ludwig Plate (1862–1937), Richard Semon (1859–1918), Wilhelm Kükenthal (1861–1922), Jürgen Harms (1885–1956), Otto Wohlberedt (1870–1945), and Dietrich Starck (1908–2001), among others (see Uschmann 1959; von Knorre 1983).

The paleontological collection of the Phyletisches Museum contains more than 30,000 objects, split into historical and contemporary sets. The historical part is marked with the acronym PMJ P and was acquired after the closure of the geoscientific institutes of Jena University in 1968 and represents a “closed collection”. All other fossils bear the acronym PMJ Pa, and specimens are still added to this contingent. In addition to type material, these collections also contain other historically valuable objects, such as the so called “Goethe-Stier” (the holotype of Bos primigenius taurus Bojanus, 1827; von Knorre and Beutel 2018) and an elephant skull that was used by von Goethe for his “Zwischenkieferstudien” (“studies on the os intermaxillare”) (Valentini 1714; Matuschek 2020). The museum also possesses a small amber collection, containing for instance important fossils of Strepsiptera, including members of the stem group and the most ancestral species of the order (Pohl et al. 2005, 2021; Pohl and Beutel 2016).

While reorganizing material and cleaning storage spaces following the closure of the museum in 2020 due to the COVID-19 pandemic, we made a surprising discovery: Another amber collection, which had been lost for several decades. In total, this collection consisted of 161 pieces, of which 76 were unlabeled. The remaining material was labeled as East African copal (“Ost-Afrika”; 3 pieces), amber from Samland (51 pieces from “Bernsteinwerke Königsberg”, 14 from Samland, and 1 piece from “Kleinkuhren”), or stated as possibly coming from Samland (“Samland?”, 15 pieces), as well as one piece from “Ostseestrand” (Baltic Sea beach). As we processed the material and started making identifications, we found a number of potential new records from specimens directly labeled as Baltic amber, with profound evolutionary implications, particularly for the Formicidae. As the new records accumulated, we became skeptical of the labeling and pursued multiple approaches to resolve the sources of the “amber” pieces in this rediscovered fossil collection of the Phyletisches Museum.

The objectives of our present study, therefore, were to: (1) Identify the source or sources of the fossils; (2) identify the insect inclusions as finely as possible; (3) provide taxonomic treatments within the realms of our expertise; and (4) to contextualize this historically overlooked collection more broadly. Toward these ends, we implemented a battery of qualitative and quantitative tests of the fossil matrices, we investigated the historical records from and associated with the Phyletisches Museum, and we applied synchrotron-radiation micro-computed tomography (SR-µ-CT) and traditional light microscopy methods to interrogate the fine-scale structure of the fossil insects in a comparative framework. Consequently, we report the results of our taphonomic investigation and key historical findings, and we provide revisionary systematic treatments for select taxa of Psocodea, Formicidae, Neuroptera, and Coleoptera.

2. Materials and methods

Note on convention: We introduce the double dagger symbol (‡) to indicate taxa that are known only from copal or Defaunation resin, to distinguish it from the single dagger (†), which is used to indicate taxa known only from amber.

2.1. Fossil specimens

All fossil pieces from the rediscovered Bernsteinsammlung (amber collection) of the Phyletisches Museum were provided with unique specimen identifiers. The identifiers are in the “Inv.-Nr. Pa.” series, which corresponds to the older accessions of the museum (von Knorre and Beutel 2018). The amber pieces were stored in three drawers in the attic of the museum and have been untouched for around 50 years. Presumably, due to the strong temperature and humidity fluctuations, the overall condition was quite poor with the fossils having brittle, deteriorated surfaces (Bisulca et al. 2012). Some of the pieces were found to be coated with an unknown type of varnish, which emitted a distinct smell during grinding. Other specimens were unconventionally glued to cardstock. We infer that the glue was some sort of epoxy, as this was commercially available in the late 1940s (Chen et al. 2019), and that the pieces were likely glued by E. Uhlmann sometime after acquisition (see section 3.1.1 below). We observed that the epoxy had “eaten” its way into the amber over time, resulting in dissolved surfaces. We removed the epoxy completely through careful grinding.

2.2. Specimen preparation

To facilitate the identification of inclusions, all amber specimens were manually ground and polished. Grinding was done with waterproof single silicon carbide abrasive paper (Robert Bosch GmbH, Robert-Bosch-Platz 1, 70839 Gerlingen, Germany) soaked in water (Sadowski et al. 2021). Initial sandpaper grainsize was chosen for each specimen individually, depending on condition and on the distance of the inclusions to the surface. In general, we used the following grainsize steps: 180, 400, 500, 1000, 1200, and 2000. Whenever possible, we made an effort to generate flat surface windows for viewing. Grinding was performed with sandpaper over a glass plate in one hand and the amber piece in the other hand. Amber pieces and glass plate were cleaned with water between every grain size step.

We experimented with different polishes such as chalk and Peek Polish (Peek Polish International, 51 Waterloo Road London NW2 7TX, United Kingdom). As the latter contains residual petroleum (Peek Premium Polish Paste Safety Data Sheet), it was used very cautiously but produced good results. Finally, we found that excellent results could be achieved by using the toothpaste Colgate® Sensation White Aktivkohle Zahnpasta (Colgate-Palmolive, 300 Park Avenue New York, NY, United States). A dab of toothpaste placed on microfibre cloth with a small amount of water was used to polish the amber pieces on all sides, until most of the remaining small scratches were no longer visible. To finish a single piece took up to three hours, as constant control under a desktop-mounted magnifying glass was mandatory to prevent grinding off inclusions.

To isolate specific inclusions, some amber specimens were cut into smaller pieces using a Dremel® 3000 (Robert Bosch GmbH, Dremel, 1800 W. Central Rd., Mt. Prospect, Illinois, U.S.) with a thin saw blade (0.1 mm) attachment. As the Dremel’s minimum speed is 10000/min, which was too fast for freehand amber cutting, we used a defective Proxxon FBS 240/E (Proxxon Inc., 130 US Hwy 321 SW, Hickory, NC 28602 USA) to create guiding cuts. The lowest revolution rate of the Proxxon is given as 5000/min, but the one that we used had a markedly lower speed. With the guiding cuts done, the faster Dremel® could be used safely. This process required very straight cuts to prevent the blade from bending and getting caught in the amber, which would occasionally cause breaking or splintering. Alternatively, we also used a hardwood saw (Heckenrose 3 fein, Augusta-Heckenrose, Werkzeugfabriken GmbH & Co KG, Rudolf-Diesel-Straße 36, 71154 Nufringen, Germany) of 0.3 mm, in this case with the tool fixed in place and the amber pulled over the blade. After polishing and cutting, the specimens were carefully dried using a microfiber cloth.

The final curatorial step was to store the fossils in individually shaped moulds of PE-Foam (SV-Schaumstoffe GmbH, Junkerstraße 10, 82178 Puchheim, Germany) in insect drawers. A slit was cut into the foam above each object, into which the matching label was inserted. A small note was placed under each amber piece (Museumspapier altweiß mit Alkalipuffer, Klug Conservation, Zollstraße 2, 087509 Immenstadt, Germany) with the corresponding inventory number.

2.3. Establishing the material origin of the fossils

As most of the specimens in the three PMJ Pa drawers lacked reliable collection information, we undertook a series of tests to determine whether the fossils had the properties of amber or copal. Specifically, we evaluated melting behavior, autofluorescence, hardness, solubility, and density. All tests were compared between the PMJ Pa material and known samples, which were either from Ethiopian, Baltic, or Burmese ambers. As the Ethiopian pieces were a loan from MAIG (Museum of Amber Inclusions, University of Gdańsk, Gdańsk, Poland), we did not sample these destructively.

To confirm that our specimens were products of plant resin rather than artefacts in plastic material, we heated a needle and attempted to insert it into the test samples to test melting behavior. We checked fluorescence using a handheld LED UV flashlight and a 6 pi LED special UV lamp with a 120° angle of radiation. To test hardness, we scratched the test pieces either against our fingernails or vice versa. For the solubility test, we used a Dremel disc saw with a diamond blade to cut small pieces from the test samples, which we then placed in 99.5% Acetone; after a few minutes, we removed the samples and pressed them between our fingers. For the density test, we filled two dishes with fresh water, and added salt to saturation to one of them, after which we placed known and unknown samples in both liquids. Finally, we sent a representative sample of 10 specimens that were either labeled as “copal” or “amber” to the International Amber Association (IAA; Gdańsk, Poland) for UV fluorescence and Fourier-transformed infrared spectroscopy (FT-IR) (Table 1).

Table 1.

Specimens tested at the IAA, their expected sources, results of the FT-IR analysis, and the color of each resin piece. Four specimens (bold) conformed to expectations based on the provided label data.

PMJ Pa Expected source Result Color Notable inclusion
5806 Baltic (succinite) Copal sensu lato Yellow Mantodea
5807 Baltic (succinite) Copal s. l. Yellow Formicidae: Lepisiota
5808 Baltic (succinite) Copal s. l. Yellow Formicidae: Dorylus
5809 Baltic (succinite) Copal s. l. Yellow Psocodea: Amphientomum
5824 Baltic (succinite) Copal s. l. Yellow Formicidae: Crematogaster
5825 Copal Copal / (Kauri gum?)1 Yellow Psocodea: Archipsocidae
5827 Baltic (succinite) Copal s. l. Yellow Formicidae: Pheidole, Dorylus
5830 Copal Succinite Orange Brachycera, Auchenorrhyncha
5855 Baltic (succinite) Succinite Orange Diptera: Tipulomorpha
5871 Baltic (succinite) Succinite Orange Archaeognatha
5858 Baltic (succinite) Succinite Orange Diptera: Tipulomorpha
5884 Baltic (succinite) Copal s. l. Yellow Formicidae: Dorylus
5889 Baltic (succinite) Copal s. l. Yellow Formicidae: Pheidole

2.4. Microscopy

Specimens were examined at the Phyletisches Museum primarily with a Zeiss Stemi SV 11 stereomicroscope and a Zeiss Axioskop compound microscope. For the stereomicroscope a maximum magnification of 40× was used. For the light microscope we used the magnifications 50×, 100× and 200×.

2.5. Photography

To remove minute scratches, the amber pieces selected for photography were polished in three successive steps with ST5000, ST7000 wet abrasive paper (Starcke, Melle, Germany), and Peek polish (Tri-Peek International, Saffron Walden, United Kingdom) or Colgate® Sensation White Aktivkohle Zahnpasta (Colgate-Palmolive, 300 Park Avenue New York, NY, United States).

For overview photographs, stacks of partially focused images were taken of the amber pieces with a Canon EOS R5 equipped with a Canon EF 100 mm f/2.8L Macro IS USM lens (Canon, Krefeld, Germany), which was mounted on a Kaiser copy stand. For focus bracketing, the internal camera software was used. The scene was illuminated with a Euromex LE.5211-230 cold light source for stereomicroscopy (Euromex, Papenkamp, Netherlands) equipped with three gooseneck lamps to adjust light conditions and prevent reflections. Underneath the camera a blurred glass plate was positioned over a black sprayed Kapa® box. The amber pieces were placed on the glass plate in a petri dish filled with distilled water as suggested by Sadowski et al. (2021). The amber was held in place with UHU Patafix (UHU, Bühl, Germany). Some pieces were photographed without water to obtain a better spatial impression.

For shots of details from single embedded specimens, a Canon Eos 7D Mark II (Canon, Krefeld, Germany) equipped with a Mitutoyo M Plan Apo 10 microscopic lens (Mitutoyo, Kawasaki, Japan) was used. To perform stack shots, the camera was mounted on a StackShot macro rail (Cognisys, Traverse City, USA). Two flashlights (Yongnuo Photographic Equipment, Shenzhen, China) illuminated the scene. The amber pieces were placed on a cover slip. Plasticine was used to level the surface. A drop of glycerine was placed on the surface of the amber piece, and the glycerine was then covered by an additional cover slip. Additional detail images were taken at the Museum für Naturkunde Berlin (MfN), where manual stacks were taken using a Zeiss Axioscope 5 with a Zeiss Achromat S 1,0 FWD 63 (Carl Zeiss AG, Oberkochen, Germany), mounted with a Canon EOS 80D (Canon, Krefeld, Germany) via a T2-T2 1,6× SLR tube.

All photographs were developed with Adobe Lightroom classic (v.11.5) (Adobe, San Jose, USA). The images (option: standard) were denoised with Topaz DeNoize AI (Topaz Labs, Dallas, USA). Zerene stacker 1.04 (Zerene Systems LLC, Richland, USA) was used to fuse the images (option: align & stack all (PMax).

2.6. Micro-computed tomography

Nine specimens (Table 2) were scanned using synchrotron radiation (SR-µ-CT) at the Imaging Beamline P05 (IBL) (Haibel et al. 2010; Greving et al. 2014; Wilde et al. 2016) operated by the Helmholtz-Zentrum Hereon at the storage ring PETRA III (Deutsches Elektronen Synchrotron—DESY, Hamburg, Germany). A photon energy of 18 keV and a sample to detector distances of 30–50 mm were used. Projections were recorded using a 50 MP CMOS camera system with an effective pixel size of 0.46 µm. 4001 projections were recorded for each tomographic scan at equal intervals between 0 and π, with an exposure time of 350 ms. When specimens were too large to fit into the field of view in the z-axis, we scanned overlapping sections and subsequently stitched them together. Tomographic reconstruction was done by applying a transport of intensity phase retrieval and using the filtered back projection algorithm (FBP) implemented in a custom reconstruction pipeline (Moosmann et al. 2014) using MATLAB (Math-Works) and the Astra Toolbox (Palenstijn et al. 2011; van Aarle et al. 2015, 2016). For further processing, raw projections were binned two times resulting in an effective pixel size of the reconstructed volume of 0.913 µm. For segmentation and visualization, the 32-bit .tif image sequences were converted to 8-bit files and downsampled twofold with Fiji (Schindelin et al. 2012), resulting in an effective pixel (voxel) size of 1.826 µm.

Table 2.

Specimens scanned at DESY; data available as Suppl. material 1.

Specimen ID Taxon name Stage/sex
PMJ Pa 5827_a Coleoptera: Platypodinae: Doliopygus cf. serratus Adult male
PMJ Pa 5870 Coleoptera: Mordellidae: †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. Adult, sex indet.
PMJ Pa 58211 Hemiptera: Auchenorrhyncha: Cixiidae Adult female
PMJ Pa 5884 Hymenoptera: Formicidae: Dorylus nigricans molestus (Gerstäcker, 1859) Adult worker
PMJ Pa 5809 Psocodea: ‡Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov. Adult female
PMJ Pa 5825 Psocodea: Archipsocidae Adult female
PMJ Pa 5889 Hymenoptera: Formicidae: ‡Pheidole cordata (Holl, 1829) Adult soldier
PMJ Pa 58742 Neuroptera: †Palaeoneurorthus sp. Adult male
PMJ Pa 58963 Arachnida: Salticidae Adult, sex indet.

2.7. 14C dating of samples

Two samples, PMJ Pa 5809 (‡Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov.) and PMJ Pa 5884 (Dorylus nigricans molestus) were dated using 14C analysis, as recommended by Delclòs Martínez et al. (2020). Amber pieces with a mass of 5 mg (PMJ Pa 5809), 6 mg (PMJ Pa 5884) and 5 mg (PMJ Pa 5889) were cut off and sent to Beta Analytic (4985 S.W. 74th Court, Miami, FL, USA 33155). Dating analyses resulted in estimated age ranges with certain likelihoods. The age range with the highest likelihood was chosen (Table 3). Based on our identifications of the copal inclusions and the history of the collections, East Africa was selected as the geographic reference for dating. We chose the psocodean as taxonomic work on the group is challenged, with presently only a handful of specialists working on them (e.g., Mockford 2018). We also chose the putative Baltic Dorylus due to its potential evolutionary and biogeographic implications.

Table 3.

14C-dating results based on the testing by Beta Analytic. The maximum age of the estimated range is listed.

14C-dated Specimen contained Results Maximum age in years
PMJ Pa 5809 Amphientomum knorrei 390 +/-30 BP 565
PMJ Pa 5884 Dorylus nigricans molestus 50 +/-30 BP 145
PMJ Pa 5889 Pheidole cordata, Lepidoptera indet 720 +/- 30 BP 746

2.8. Data segmentation and rendering

µ-CT-image stacks were segmented and 3D-reconstructed using Amira 6.0.1 (Thermo Fisher Scientific) and Dragonfly 2022.1 (Object Research Systems,). Image (tif) stacks and isosurfaces were exported with the Amira macro “Multi-Export” (Engelkes et al. 2018). The isosurfaces were reduced and smoothed with following parameters: ItTotal: 5; smooth: iteration: 4, lambda: 0.6; reduction: 0.7. Tiffs were volume rendered in VGStudio Max 2.0 (Volume Graphics) using the option Phong reflection model. The isosurfaces were further smoothed (modifier: smooth and option shade smooth) with Blender 3.2.0 (Blender Foundation). The 3D-Models were uploaded to the 3D repository Sketchfab (URL: using the free blender plugin: Sketchfab for Blender 1.5.0 (URL:

2.9. Image plates

Image plates were compiled using Adobe Photoshop (v. 24.1.0) (Adobe, San Jose, USA). Lettering was added with Adobe Illustrator (v. 27.2).

2.10. Repositories

Specimens evaluated in the present study, and also for the use of comparison to each other, were from the following collections:

BEBC Brendon E. Boudinot research collection, Frankfurt am Main, Germany

MAIG Museum of Amber Inclusions, University of Gdansk, Poland.

PMJ Phyletisches Museum Jena, Germany.

MNHB Museum für Naturkunde Berlin, Germany.

MWC Michael Weingardt research collection, Jena, Germany.

SMNS Staatliches Museum für Naturkunde Stuttgart, Germany.

USNM U.S. National Museum of Natural History, Washington, D. C., U.S.A.

2.11. Data availability

The raw scan data will be made available at MorphoSource upon acceptance.

3. Results

3.1. Fossil sources

3.1.1. Fossil provenance

Collector. Unknown.

Date. Unknown. It is likely that the 161 fossil pieces in the collection were acquired by the Phyletisches Museum in several batches between 1920 and 1930 (see below).

Circumstantial evidence. By the handwriting of the label for specimen PMJ Pa 5827, the date of collection is estimated between 1920 and 1930 (personal communication with Uwe Dathe, Historische Sammlungen ThULB, 15.07.2022 and Alexander Gehler, Geowissenschaftliches Zentrum der Georg-August-Universität, 14.07.2022). The label for specimen PMJ Pa 5827 has two different scripts on each side, which cannot be clearly assigned to any handwriting samples in the museum’s archives. Furthermore, the former curator of the museum, Dietrich von Knorre, stated that Eduard Uhlmann (1888–1974) was in charge of the small “Bernsteinsammlung” (amber collection); Uhlmann was a scientific assistant, later conservator at the Phyletisches Museum Jena while it was under the directorship of Ludwig Plate (director from 1909–1935), and later became associate professor (ao. [außerodentlicher] Professor 1950) and director of the Phyletisches Museum from 1952 till 1954.

In accordance with the statements above, there are handwritten labels on nine specimens (Pa 5828, 5829, 5836, 5871, 5873, 5874, 5875, 5882, and 5885) which can be assigned to E. Uhlmann and his wife Frida Uhlmann (born Preiss, 1894–1981). This assessment is unambiguous as the Uhlmanns re-sorted numerous drawers in the entomology collection, which were labelled by her (Krogmann et al. 2007). Moreover, von Knorre stated (25.07.2022) that Uhlmann (Fig. 1) bequeathed the small amber collection to him after retirement, which von Knorre later added to the museum’s collection. We screened the archives of the Friedrich Schiller University (21.07.2022) and the Phyletisches Museum (21–22.07.2022) but did not discover invoices or personal communication of Uhlmann and Plate. In sum, how exactly the small amber collection found its way into the museum cannot be confidently resolved at present.

Figure 1. 

Eduard Uhlmann around 1955. Archive of the Phyletisches Museum XXVII.

Listed localities. Of the 161 numbered pieces, 76 lacked locality information and one additional number was associated with human-made beads without further information (Pa 5911; not included in the total count). Of the remaining 85 pieces, 21 have labels indicating a Baltic origin and three are marked as copal from East Africa, such as Pa 5829, which has a handwritten label stating “Kopalinsect Ost-Afrika Diluvium”. One of the putative Baltic pieces, Pa 5827, has a handwritten label “Fundstück von Kleinkuhren Samland” (Filino), while 15 are marked with “Samland?” and the derivation of 51 of the other presumptive amber specimens is indicated as Samland Bernsteinwerke Königsberg on the labels, with an authentic invoice from the “Preuß. Bergwerks- und Hütten-Akt.-Ges. Zweigniederlassung Bern-steinwerke Königsberg Pr. for 1 M” for Pa 5863. For a discussion of the Samland and Kleinkuhren localities, see also section 4.2.

Qualitative tests. Despite the labels, the locality or localities of origin are not as clear as the first impression suggested. As it is not possible to discriminate copal and amber reliably based on the visual appearance alone (e.g., Federman 1990), we conducted a series of qualitative tests (see section 2.3), most of them at the Phyletisches Museum. Overall, the qualitative tests were contradictory and inconclusive. All pieces labelled as amber floated in saltwater and all labelled as copal sunk, apparently confirming the original labels. However, not a single piece in the collection emitted blue light under UV, while amber specimens of known provenance from the BEBC (burmite, succinite) and MAIG (Ethiopian amber) did. By burning the different samples from the PMJ Pa collection, every piece sizzled and produced black smoke, as expected for amber. Only one sample (Pa 5809) showed clear white smoke, but burning a larger piece yielded black smoke. Thus, the expected difference—that amber burns and copal melts—was not observed. When only small pieces were left, both copal and amber melted. Most conspicuous was a sweet odor produced by burning a larger piece of copal (from Pa 5809), which clearly distinguished it from true amber. This scent was not detected with smaller pieces, however.

Quantitative tests. For quantitative testing, additional small pieces were cut off and sent to the International Amber Association (IAA, 1 Warzywnicza Street, 80-838 Gdańsk, Poland) and checked with the UV/VIS and the FT-IR method (Table 1). The results from these analyses contradicted those from the qualitative tests and showed that all light-yellow pieces were copal, including those with Dorylus. In contrast, the darker, orange-colored pieces were true succinite (Baltic amber), including the one with †Yantaromyrmex. Finally, the 14C dating yielded an age of only ~145 years old for the piece containing the Dorylus. Therefore, this and other pieces with similar biotic inclusions are identifiable as Defaunation resin (sensu Solórzano-Kraemer et al. 2020), while the estimated age for the Amphientomum-bearing specimen is ~390 years old.

Biotic evidence. Ultimately, our final interpretations of the geological source of the putative amber pieces were based on the combined weight of evidence from the IAA results and the insect inclusions themselves. While it was exciting to consider the possibility that the Dorylus, Lepisiota, Pheidole, and Crematogaster ants were first records from Baltic amber, our µ-CT scan of the Dorylus revealed that it is identifiable as an extant subspecies. Moreover, this subspecies, Dor. nigricans molestus (Figs 2A–C, 3, Appendix 1: Fig. A1), was previously recorded from reliably identified Tanzanian copal by DuBois (1998) (see section 4.2.2 below). Another critical element of biotic evidence was the large piece PMJ Pa 5827, which contained another Do. n. molestus as well as a distinctive platypodine beetle (Curculionidae; “ambrosia beetles”, “pinhole borers”). Based on our µ-CT rendering of the beetle, Bjarte Jordal (01 Nov 2022) identified it as either Doliopygus serratus or Dol. cf. serratus (Figs 4A–C, Appendix 1: Fig. A2), which in either case represents bark beetle populations that are extreme generalists, and presently distributed throughout Southern, Central, and West Africa (Beaver and Löyttyniemi 1985). Several other amber pieces from the PMJ Pa contained sweat bees (Meliponini) that closely resembled specimens from known African copal pieces at the SMNS. All these aforementioned fossil pieces were light yellow, while other specimens—without these distinctive taxa—were dark and of a pinkish red color. Among these darker specimens was an ant definitively identifiable as †Yantaromyrmex geinitzi, the type species of a Baltic-amber-endemic genus. In section 3.2, we outline the complete list of taxa that we identified in the PMJ Pa collection, as well as the results of investigations on the origin of material compared to the point of starting our investigations.

Figure 2. 

Overview photo of a select piece of Defaunation resin (A) and a piece without dating analysis performed (B). A. Piece PMJ Pa 5884, 14C dated as about ~145 years old, with inclusions of several Dorylus nigricans molestus workers; B. piece PMJ Pa 5827 with the inclusion of the scanned Doliopygus cf. serratus as well as another Do. n. molestus worker. Arrows mark scanned specimens.

Figure 3. 

A–C. 3D reconstruction of Dorylus nigricans molestus (Formicidae: Dorylinae) preserved in piece PMJ Pa 5884. A. Habitus lateral; B. Habitus frontal; C. Habitus dorsal. See section 4.2.1 below for diagnostic remarks.

Figure 4. 

3D reconstruction of Doliopygus cf. serratus (Curculionidae: Platypodinae) preserved in piece PMJ Pa 5827. A. Habitus lateral; B. Habitus dorsal; C. Habitus ventral.

3.2. Fossils of the PMJ Pa amber collection and the origin of material

In Table 4 we provide a list of all specimens sorted taxonomically, including reference to the museum accession numbers.

Table 4.

All identified taxa from the PMJ Pa amber collection.

Taxon Matrix PMJ Pa
(Trichomes) Succinite 5872
(Leaf fragments) first 4 Copal s. l, 5886 Copal s. l, all others Succinite 5811, 5820, 5826, 5886, 5839, 5840, 5843, 5848, 5849, 5851, 5855, 5856, 5861, 5862, 5867, 5870, 5883, 5885, 5910
(Indet.) Succinite 5798, 5840, 5854, 5876
Linyphiidae Copal s. l 5809
Philodromidae Succinite 5838
Thomisidae Succinite 5877
Zodariidae: cf. Trygetus Copal s. l 5807
Zodariidae Succinite 5876
Uncertain: Araneidae, Palpimanidae, Philodromidae, Salticidae, Thomisidae First two Copal s. l, others Succinite 5827, 5890, 5843, 5879, 5878, 5881
(Indet.) Succinite 5859
(Indet.) Succinite 5903, 5908
Symphypleona Succinite 5908
Machilidae Succinite 5828
(Indet.) Succinite 5871, 5872
Blattodea Succinite 5841
Isoptera first 11 Copal s. l, other Succinite 5794, 5798, 5802, 5803, 5811, 5815, 5818 5819, 5822, 5826, 5827, 5848, 5871
Mantodea Copal s. l 5806
Aphididae Succinite 5860, 5885
Anthocoridae Copal s. l 5827
Cicadellidae Copal, Succinite, Succinite 5827, 5847, 5852
Cixiidae Copal s. l 5821
Issidae Copal s. l 5821
Psyllidae Copal s. l 5798
Coccoidea Succinite 5856
Fulgoroidea Copal s. l 5793
Aleyroidea Copal s. l 5822
(Auchenorrhyncha) Copal s. l 5809
Amphientomum knorrei sp. nov.
Copal s. l 5908
Archipsocidae Kauri gum? 5825
Liposcelididae Copal s. l 5827
(Indet.) Copal s. l 5820, 5822
Anthophila: Apinae Copal s. l 5795, 5807, 5814, 5816, 5817, 5826, 5892
Anthophila: Apinae: Meliponini Copal s. l 5796, 5798, 5800, 5806, 5815, 5822, 5824, 5888, 5893
Anthophila: (indet.) Copal s. l 5793, 5810, 5894
Bethylidae Copal s. l 5823
Braconidae: Cheloninae Copal s. l 5896
Braconidae: (indet.) Copal s. l 5823
Chalcidoidea Copal s. l 5816, 5819, 5820, 5821
Formicidae: Camponotus Copal s. l 5829
Formicidae: †Ctenobethylus Succinite 5851, 5874, 5893, 5903
Formicidae: Crematogaster Copal s. l 5824
Formicidae: Dorylus n. molestus Copal s. l 5808, 5827, 5884
Formicidae: Ponerini: cf. Hypoponera Copal s. l 5819
Formicidae: Lepisiota Copal s. l 5807
Formicidae: ‡Pheidole cordata Copal s. l 5827, 5889
Formicidae: †Yantaromyrmex geinitzi Succinite 5856
Formicidae: Dolichoderinae Copal s. l 5817, 5821
Ichneumonidae Succinite 5869
Platygastroidea: Platygastridae Copal s. l 5889
Platygastroidea: Scelionidae sensu lato Copal s. l, Succinite 5809, 5836
Platygastroidea: (indet.) Copal s. l, Succinite, Succinite 5821, 5846, 5877
(Aculeata) Copal s. l 5822, 5890
(Parasitica) Copal s. l 5808, 5891
(Indet.) Succinite 5843
Nevrorthidae: †Palaeoneurorthus Succinite 5874
Cantharidae Succinite 5863
Chrysomelidae: Bruchinae? Copal s. l 5827
Chrysomelidae: Alticini? Copal s. l 5810
Chrysomelidae? Copal s. l 5892
Curculionidae: Doliopygus cf. serratus Copal s. l 5827
Curculionidae: Platypodinae Copal s. l 5798, 5805, 5807, 5812, 5814, 5816, 5819
Elateridae Succinite 5851, 5866
Mordellidae: †Baltistena nigrispinata sp. nov. Succinite 5870
Staphylinidae Copal s. l, Succinite 5828, 5861
Bostrichoidea? Succinite 5836, 5883
Staphylinoidea? Succinite 5851
(Polyphaga) Copal s. l, Succinite, Copal s. l 5819, 5885, 5891
Ceratopogonidae Succinite, last one Copal s. l 5848, 5863, 5864, 5889
Chloropidae Succinite 5836
Dolichopodidae Succinite 5837
Mycetophilidae Succinite, last Copal s. l 5848, 5885, 5901, 5890
Sciaridae Succinite, 5851, 5864
Phoridae Copal s. l 5808, 5823, 5827
Psychodidae Copal s. l 5896
Sciaroidea Copal s. l, Succinite 5809, 5840
(Tipulomorpha) Succinite 5855, 5858
(Brachycera) First 7 Copal s. l , all other Succinite 5795, 5807, 5811, 5815, 5822, 5827, 5830, 5836, 5839, 5844, 5846, 5849, 5853, 5854, 5857, 5862, 5865, 5867, 5868, 5871
(Muscomorpha) Copal s. l 5797, 5799, 5809, 5891
(Calyptrata) Copal s. l 5586
(Nematocera) first 5 Copal s. l, all following Succinite 5808, 5827, 5830, 5891, 5895, 5836, 5837, 5839, 5844, 5846, 5854, 5857, 5858, 5861, 5862, 5870, 5871, 5872, 5874, 5877, , , 5897, 5902, 5903, 5909
(Indet.) first three Copal s. l, other Succinite 5821, 5892, 5896, 5843, 5882, 5898, 5905
(Indet.) first 3 Copal s. l, last Succinite 5797, 5804, 5889, 5842,
Annulipalpia Succinite 5850, 5875
Integripalpia Succinite 5863
(Indet.) Succinite, Copal s. l 5845, 5891
(Indet.) Succinite 5903

The initial situation of the material, with a rather chaotic sorting, shows that almost half of the material was without evidence of origin. Around 40% were labelled as Baltic amber, while 3 pieces were labeled as copal (Suppl. material 1). Overall, almost 10% were labelled, but with a question mark, which is not reliable information in any case.

After identification, provenance research and chemical analysis the origin of most of the material could be solved confidently. One of the biggest surprises was that 7 pieces are of Kauri origin. Now, more than half of the material is of clear Baltic origin. The biggest switch was from pieces without evidence and the 3 pieces labelled as copal, as with 44% a sizable number in the collection is indeed East-African copal (Suppl. material 2).

3.3. Systematic entomology

3.3.1. Order Psocodea: Synopsis of higher taxa in the PMJ Pa

Mostly families represented by material in the PMJ Pa are reviewed below. The identification of PMJ Pa material was based on the keys of Smithers (1990), with Taylor (2013) for the amphientomid. Specific details about the fossil deposits and their ages in this and other synopsis header sections are drawn from Paleobio (2022); we have included these for the geological information and to ease future divergence-dating phylogenetic analysis. Taxonomic information was drawn in part from the Psocodea Species File Version 5.0 (Johnson et al. 2023) database. Family Amphientomidae Enderlein, 1903. [Note 1]

Amphientominae Enderlein, 1903 amber species:

I. Genus Amphientomum Pictet, 1854. [Note 2].

A. Oise amber [France, Le Quesnoy; Eocene, Ypresian, 56.0–47.8 Mya].

1. †Am. parisiense Nel, Prokop, De Ploeg & Millet, 2005.

B. Baltic ambers [Eocene, 37.8–33.9 Mya].

2. †Am. (Amphientomum) leptolepis Enderlein, 1905. [Note 3].

3. †Am. (Amphientomum) paradoxum Pictet, 1854. [Type species!]

4. †Am. (Palaeoseopsis) colpolepis Enderlein, 1905.

C. African resin [ca. 390 ± 30 years].

5. ‡Am. knorrei Weingardt, Bock & Boudinot, sp. nov. [Note 4].

II. Genus Lithoseopsis Mockford, 1993.

D. Mexican amber [Miocene, 23.0–16.0].

1. †Li. elongata (Mockford, 1969).

III. Genus †Proamphientomum Vishnyakova, 1975.

E. Taimyr amber [Russia; Cretaceous, 85.8–83.5 Mya].

1. †Pr. cretaceum Vishnyakova, 1975.

Amphientomidae amber species incertae sedis:

IV. Genus †Arcantipsocus Azar, Nel & Néraudeau, 2009.

F. Charentese amber [France; Cretaceous, 105.3–99.6 Mya].

1. †Ara. courvillei Azar, Nel & Néraudeau, 2009. [Note 5].

Note 1. As part of our ongoing psocodean revisionary investigations, we provide an extended discussion of Amphientomum (see below).

Note 2. A list of all extinct and extant Amphientomum species is provided in Table 5. With the addition of the new species described herein, there are 20 species attributed to this genus (Johnson et al. 2023), of which four are extinct; it is unknown if the species described herein is still extant.

Table 5.

All currently described species of the genus Amphientomum. It is uncertain whether ‡Am. knorrei sp. nov. is extant. The type species of Palaeoseopsis is bolded and that of Amphientomum is bolded and in cells with grey shading.

# Taxon Authors Distribution
I Am. colpolepis (Enderlein, 1905) Baltic amber
II Am. knorrei Weingardt, Bock & Boudinot, 2024 sp. nov. East African copal
III Am. leptolepis Enderlein, 1905 Baltic amber
IV Am. paradoxum Pictet, 1854 Baltic amber
V Am. parisiense Nel, Prokop, De Ploeg & Millet, 2005 French Oise amber
1 Am. acuminatum Smithers, 1964 Madagascar
2 Am. aelleni Badonnel, 1959 Republic of the Congo
3 Am. annulicorne Badonnel, 1967 Madagascar
4 Am. annulitibia Smithers, 1999 Tanzania
5 Am. dimorphum Badonnel, 1967 Madagascar
6 Am. ectostriolate Li, 1999 China
7 Am. flexuosum Badonnel, 1955 Angola, Nigeria
8 Am. hieroglyphicum Badonnel, 1967 Madagascar
9 Am. loebli (Badonnel, 1979) Ivory Coast
10 Am. mimulum Badonnel, 1967 Madagascar
11 Am. montanum Badonnel, 1967 Madagascar
12 Am. pauliani Smithers, 1964 Madagascar
13 Am. punctatum Badonnel, 1967 Madagascar
14 Am. simile Badonnel, 1967 Madagascar
15 Am. striaticeps Badonnel, 1967 Madagascar

Note 3. The species †Am. leptolepis might be a variant of †Am. paradoxum, as these two taxa are distinguished by only a few characters (Enderlein 1911). Specifically, †Am. leptolepis is differentiated from †Am. paradoxum by the following: (1) fore wing with very long and slender scales; (2) sides of the scales parallel; and (3) the count of ctenidiobothria on the hind basitarsus is 36 (vs. 29–34 in †Am. paradoxum) (Enderlein 1911). It should be noted that the description of †Am. leptolepis was based on two specimens (Enderlein 1911, p. 295) and no additional information on this species was published since then, to the best of our knowledge. Overall, we consider the scale shape as not fully reliable, yet we retain the species status of these two taxa pending more detailed study.

Note 4. We describe this new species from African resin in the PMJ Pa collection. See section below for our treatment of this taxon.

Note 5. Mockford et al. (2013) synonymized †Arcantipsocidae Azar, Nel & Néraudeau, 2009 with Amphientomidae, arguing that a dark, thickened pterostigma is a homoplastic feature across the order Psocodea, thus cannot be relied upon singly for placement in Psocomorpha. They left †Arcantipsocus unplaced within the family but further recognized features that the genus shares with modern Amphientomidae, i.e., the hindwing venation and the shape of maxillary palps, head, and forewings. Family Liposcelididae Broadhead, 1950

Liposcelidinae Broadhead, 1950 amber and copal species:

I. Genus Liposcelis Motschulsky, 1852.

A. Baltic ambers [Eocene, 37.8–33.9 Mya].

1. †Li. atavus Enderlein, 1911.

B. Mexican amber [Miocene, 23.0–16.0].

2. †Li. sp. [Note 1]. [f].

C. Zanzibar copal [Pleistocene?].

3. ‡Li. resinata (Hagen, 1865).

Embidopsocinae Broadhead, 1950 amber species:

II. Genus Belaphopsocus Badonnel, 1955.

D. Dominican amber [Miocene, 20.4–13.8 Mya].

1. †Bs. dominicus Grimaldi & Engel, 2006.

III. Genus Belaphotroctes Roesler, 1943.

B. Mexican amber [Miocene, 23.0–16.0].

1. †Bt. ghesquierei Badonnel, 1949.

E. Zhangpu amber [Miocene, 16.0–13.8].

1. †Bt. grimaldii Engel & Wang, 2022.

IV. Genus Embidopsocus Hagen, 1866.

F. Oise amber [France, Le Quesnoy; Eocene, Ypresian, 56.0–47.8 Mya].

1. †Em. eocenicus Nel, de Ploëg & Azar, 2004.

A. Baltic ambers [Eocene, 37.8–33.9 Mya].

2. †Em. pankowskiorum Engel, 2016.

G. Bitterfeld amber [Eocene, 38.0–33.9 Mya].

3. †Em. saxonicus Günther, 1989.

Liposcelididae amber species incertae sedis:

II. Genus †Cretoscelis Grimaldi & Engel, 2006.

H. Kachin amber [Myanmar; Cretaceous, 99.6–93.5 Mya].

1. †Csc. burmitica Grimaldi & Engel, 2006.

Note 1. Mockford (1969) recognized a species of Liposcelis from Mexican amber that he left undescribed as insufficient structural detail, i.e., cuticular microsculpture and chaetotaxy, was observable. Family Archipsocidae Pearman, 1936

Archipsocinae Pearman, 1936 amber species:

I. Genus Archipsocopsis Badonnel, 1948.

A. Mexican amber [Miocene, 23.0–16.0].

1. †Ari. antigua (Mockford, 1969).

II. Genus Archipsocus Hagen, 1882.

B. Baltic ambers [Eocene, 37.8–33.9 Mya].

1. †Aru. puber Hagen, 1882.

3.3.2. Taxon description (Psocodea)

Family Amphientomidae Enderlein, 1903

Subfamily Amphientominae Enderlein, 1903

Amphientomum Pictet, 1854

= Amphicetomum Hagen, 1859.

= Palaeoseopis Enderlein, 1925 syn. nov. (Type species: †Am. colpolepis Enderlein, 1905 by original designation.).

Type species

Am. (Amphientomum) paradoxum Pictet, 1854.


Pictet (1854) first described the genus from Baltic amber. Enderlein (1905, 1911) defined several character states that define the genus Amphientomum. These include a large body size, a relatively small ocellar area where the distance between the ocelli is short, a lack of spur sensilla on the maxillary palpomeres, an elongated and narrow fourth maxillary palpomere, labial palps with two articles, antennal flagellum with secondary annulation, presence of a complete R1 vein in the hindwing, and perhaps more surprisingly the occurrence of only 13 flagellomeres (Enderlein 1911, p. 333). The number of antennomeres might be an oversight by Enderlein (1911), as Hagen (1882) had already described the number of articles (15) correctly. In his revision of Pearman’s (1936) phylogenetic system of Psocoptera, Roesler (1944) provided morphological characters to define previously established groupings including the Amphientomidae. In so doing, Roesler designated the previously established genus Palaeoseopsis Enderlein, 1925 as a subgenus of Amphientomum. As such, Am. (Palaeoseopsis) is supposed to differ from Am. (Amphientomum) by the open basiradial cell, the lack of the basal section of Rs in the hindwing, and the emarginate scale tips (Enderlein 1925; Roesler 1944). Badonnel (1955) went a step further and proposed that the subgenus Palaeoseopsis can be removed entirely but did not follow through on this action. It should be noted that an open basiradial cell in the hindwing occurs in all species of the genus that are outside the subgenus Am. (Amphientomum), as in most species only a short spur vein of the basal section of Rs is present or the basal section of Rs is entirely missing. Phylogenetic studies on this genus are lacking and the monophyly of the subgenera Am. (Palaeoseopsis) and Am. (Amphientomum) is therefore questionable, as they are neither supported by morphological apomorphies, nor by molecular data. We therefore formalize the synonymy of Amphientomum and Palaeoseopsis j. syn., syn. nov. The diagnostic characters of the genus Amphientomum are as follows after the identification key by Taylor (2013): presence of wings, the vein M in the hindwing simple, presence of three ocelli, the lateral ocelli closer to each other than to compound eyes, the vein R1 reaching the wing margin in the hindwing, and the distal section of the vein Sc in the forewing present. See also the Remarks section for †Am. knorrei sp. nov.


The term sulcus is used here when an external line or furrow corresponds with an internal ridge, i.e., a strengthening ridge (Girón et al. 2023). If no internal ridge is present but a narrow zone of weakness, we use the term suture (e.g., frontal suture). The typical coronal suture (part of the ecdysial suture) of other insects corresponds with an internal ridge in adult psocids and is therefore here classified as a coronal sulcus. The frontal sutures (part of ecdysial suture) are similarly developed as in other insects, without an internal strengthening ridge. The term epistomal sulcus is used as synonym of the frontoclypeal line.

Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov.


We dedicate this species to Dietrich von Knorre, whose lifework was to establish and curate the collection of the Phyletisches Museum. Besides being a natural conservationist and a dedicated teacher of students, von Knorre was the curator of the Museum from 1969 till 2003, during which time he dealt with nearly every item in the entire collection. In addition to his more than 270 publications (Köhler 2019), he has done meticulous research on the history of an immense number of objects and has become the museum’s “living archive”. With the newly discovered specimen bearing his name, we want to express our gratitude for his continuous support and contributions to the Phyletisches Museum.

Type materials

Holotype. PMJ Pa 5809, Copal (East African?). Female. Interactive cybertype: Appendix 1: Fig. A3.

Paratypes. None.


Macropterous. Wings and body covered with scales. Scales apically straight or medially incised. Epistomal sulcus complete and corresponding epistomal ridge wide. Genae long. Vertex narrow and rounded. Three ocelli of similar size present, forming an isosceles triangle. Lateral ocelli closer to each other than to compound eyes. Compound eyes large and their upper margin reaching uppermost margin of vertex. Antenna with 15 articles. Flagellomeres with secondary annulation. Maxillary palps with four articles, a minute basal article and a long and cylindrical last palpomere that is rounded distally. No conical sensillum visible on second maxillary article. Tip of lacinia with long lateral region bearing several rounded denticles, and a shorter truncated median tine. Water-vapor absorption-apparatus on hypopharynx present. Labial palps with 2 articles, the basal one short and small, the distal one large, round and flattened. Pronotum strongly reduced, barely visible dorsally as mesonotum exceeds its height. All tarsi with 3 articles. First tarsomere of hind leg very long, with 24 ventral ctenidiobothria. Claws with 1 minute preapical tooth and small ventral subapical microtrichia. Pulvilli absent. Metacoxal interlocking mechanism present. Profemur with at least 27 small spines. Tibiae with horizontal rings of brown scales. Protibia equipped with only 1 distinct apical spur. Mesotibia with 3 long apical spurs. Metatibia with 6 (3 long and 3 short) apical spurs. Unique scale patterning on forewing present, differentiating it from related species. Anteroproximal region of forewing densely covered with dark brown scales. Distal part of Sc in forewing present, closing pterostigma proximally. Rs and M connected by cross vein in forewing. Areola postica of triangular shape and distinctly longer than high. CuP and A1 do not fuse at forewing margin. Tip of R1 vein of hindwing reaching anterior wing margin. Proximal section of Rs in hindwing absent, basiradial cell open. Hindwing with simple M vein. Conspicuous color patterning on abdomen with pale spots on darker brown patches. Clunium unmodified. Epiproct and paraproct simple, the latter with inconspicuous sensorium. Subgenital plate simple and rounded apically with long setae. T-shaped sclerite not visible. Valvulae largely hidden by subgenital plate, but all three pairs present and external valve bilobed.


Measurements (in mm): Body length: 3.7. Head length: 1.4 (labrum–vertex). Head width: 1.2 (between compound eyes). Length of antennae: 2.21. Length of scape: 0.10. Length of pedicel: 0.10. Length of flagellomeres: f1 = 0.29, f2 = 0.27, f3 = 0.23, f4 = 0.26, f5 = 0.18, f6 = 0.15, f7 = 0.11, f8 = 0.12, f9 = 0.09, f10 = 0.10, f11 = 0.06, f12 = 0.09, f13 = 0.07. Length of maxillary palpomeres: I = 0.06, II = 0.24, III = 0.14, IV = 0.22. Length of thorax: 0.90. Length of forewings: 3.9. Width of forewings: 1.4 (largest width). Length of hindwings: 2.8. Width of hindwings: 1.0. Length of hindlegs: F = 0.93, T = 1.54, t1 = 1.03, t2 = 0.15, t3 = 0.15. Length of abdomen: 2.2. Length of subgenital plate: 0.78. Length of epiproct: 0.24. Length of paraproct: 0.3.

Note. Different measurements based on photos or renders result from the strong curvature of different body parts. Therefore, we used the 3D reconstructions for most measurements and the photos for measuring the length of metatarsomeres and the forewing.

Indices (measured from dorsal, after Lienhard 1998): IO/D: 1.21. PO/D: 0.73.

Coloration. Head capsule dark brown. Postclypeus with few small darker spots. Labrum brown, slightly darker than rest of head. Antennal flagellum light brown to middle brown, becoming brighter distally. Maxillary palpomeres dark brown with apical regions of articles 2 and 3 lighter in coloration. Labial palpomeres light brown with dark spot on central area of flattened surface of palpomere 2. Compound eyes light brown, with darker circular areas of pigmentation. Ocelli dark brown, but median ocellus slightly brighter. Thorax slightly darker in color than head. Legs brown, less strongly pigmented apically. Forewing membrane of light brown tone, brighter towards apex. Hindwing almost hyaline, slightly more yellowish to brownish towards base. Wing veins in light brown to brownish tone or almost hyaline. Abdomen with conspicuous pattern of pale ocher patches surrounded by dark brown areas. Subgenital plate nearly uniformly dark brown, but lateral base paler. Ovipositor valves light brow with slight yellowish tint. Scales light brown to dark brown, with tips generally darker than base. Color patterns of head, compound eyes and abdomen possibly faded and with artifacts, due to non-ideal preservation in resin and subsequent suboptimal storage.

Head capsule. The head is distinctly higher than wide and anteroposteriorly flattened, thus appearing almost scale shaped. In dorsal view it appears wider than long. The vertex (Figs 5A, 6B, 7A, ve) is narrow and rounded, while the frontal area is relatively large (Figs 5A, 6A, 7A, B, fr). In frontal view, the dorsal margin of the vertex is almost straight with only a very slight concave impression laterad the median line. Three ocelli (Fig. 6A, oc) are placed flat on the frons and vertex without a cuticular elevation, closer to each other than the lateral ocelli to the compound eyes. The median ocellus is slightly smaller than the lateral ones. The ovoid and relatively large compound eyes are not extending over the upper margin of the head, with a wide distance between them. The circumocular ridge (Figs 8A, B, 9, cor) is well-developed and wide, forming an oval that is slightly curved inwards on its posterior side. Externally, a conspicuous coronal sulcus (Fig. 6B, cs) is discernable, corresponding with the well-developed internal median coronal ridge (Figs 8B, 9, cr). The frontal sutures are present but indistinct. The external epistomal sulcus (Figs 5A, 6A, 7A, B, 10A, eps) is complete and semi-oval, with the postclypeus (Figs 5A, 6A, 7A, B, 10A, pcl) extending ventrally over the ventral genal margin. The large postclypeus is not strongly convex or bulging but rather scale-like. It is approximately twice as long as the frons. Two slit-like impressions begin on the ventral end of the postclypeus slightly laterad the midline and run in an acute angle approximately towards the postclypeal midlength where they obliterate. The internal epistomal ridge (Figs 8A, B, 9, epr) is wide (epistomal ridge in sagittal section longer than half of the length of the entire postclypeus, Fig. 8A, B). The anteclypeus (Figs 6A, 7A, B, 10A, acl) is relatively small and more than 4 times as wide as long, wider proximally than the ventral margin of the postclypeus and enveloping parts of it. The anterior tentorial pits (Fig. 7A, B, atp) are visible directly at the ventral margin of the epistomal ridge, almost adjacent to the anterior mandibular articulation. The posterior tentorial pits dorsad the insertion of the maxillary stipes to the head capsule are slit-like (visible in µCT scan). The well-developed tentorium is composed of large anterior (Figs 9, 11I, ata) and posterior arms (Figs 9, 11I, pta), a narrow corpotentorium (Figs 9, 11I, ct) and thin dorsal arms (Figs 9, 11I, dta). The anterior arms are anteriorly twisted and do not fuse with each other posteriorly. The very thin dorsal arms are not entirely preserved. The right dorsal arm is ending before it reaches the antennal insertion, while the left arm is almost completely missing in the specimen. The corpotentorium is compact and short and the posterior arms straight and thick. A well-developed postoccipital ridge (Fig. 9, por) and external postocciput form the posteriormost cephalic region. The head is posteriorly open, i.e., no genal-, hypostomal- or postgenal bridge or gula is developed but the posteroventral closure of the head is formed by the weakly sclerotized postmentum (Fig. 9, pom).

Figure 5. 

A–H. Photography of ‡Amphientomum knorrei sp. nov. preserved in piece PMJ Pa 5809. A. Habitus in dorsofrontal view; B. Habitus in ventrocaudal view; C. Right metafemur and -tibia in posterior view, rings of brown scales on metatibia; D. Distal portion of left hindleg with claw, arrow indicates preapical tooth; E. Basitarsomere of hindleg, arrows indicate ctenidiobothria; F. Right antennal flagellum, flagellomere 5, arrows indicate secondary annulation; G. Scales, arrow indicates scale type III; H. Tip of right hindwing with scales, arrows indicate scale type I and II.

Figure 6. 

A–C. 3D-reconstruction of ‡Amphientomum knorrei sp. nov. A. Habitus in frontal view; B. Habitus in dorsal view; C. Habitus in ventral view. Abbreviations: acl = anteclypeus, cs = coronal sulcus, gl = glossa, lap = labial palp, lb = labrum, mxp = maxillary palp, oc = ocellus, pcl = postclypeus, pgl = paraglossa.

Figure 7. 

A–C. 3D-reconstruction of ‡Amphientomum knorrei sp. nov. A. Habitus in left lateral view; B. Habitus in right lateral view; C. Subgenital plate in ventral view. Abbreviations: acl = anteclypeus, atp = anterior tentorial pit, dov = dorsal valve, epp = epiproct, eps = epistomal sulcus, fr = frons, ga = galea, ge = gena, gef = genal fovea, ges = genal sulcus, lap = labial palp, lb = labrum, lc = lacinia, md = mandible, occ = occiput, pap = paraproct, pcl = postclypeus, ppf = palpifer, sgp = subgenital plate, st = stipes, ve = vertex.

Figure 8. 

A–B. 3D-reconstruction of ‡Amphientomum knorrei sp. nov. A. Internal view from left side, sagittal cut; B. internal view from right side, sagittal cut. Abbreviations: car = circumantennal ridge, cor = circumocular ridge, cr = coronal ridge, epp = epiproct, epr = epistomal ridge, fl = foreleg, ger = genal ridge, hl = hindleg, lap = labial palp, lc = lacinia, ml = midleg, msf = mesofurca, msp = mesophragma, mtf = metafurca, mtp = metaphragma, pap = paraproct, parr = parapsidial ridge, prf = profurca, prn = pronotum, sgp = subgenital plate.

Figure 9. 

3D-reconstruction of ‡Amphientomum knorrei sp. nov. Internal view of head from left side, sagittal cut. Abbreviations: acl = anteclypeus, amdad = apodeme of mandibular adductor, asas = apodeme of salivary sclerite, ata = anterior tentorial arm, car = circumantennal ridge, cor = circumocular ridge. cr = coronal ridge, ct = corpotentorium, dta = dorsal tentorial arm, epr = epistomal ridge, ga = galea, ger = genal ridge, hy = hypopharynx, lap = labial palp, lb = labrum, lc = lacinia, md = mandible, pcl = postclypeus, pom = postmentum, por = postoccipital ridge, prm = prementum, pta = posterior tentorial arm, sas = salivary sclerite, sit = sitophore.

Figure 10. 

A–F. Photography of ‡Amphientomum knorrei sp. nov. A. Right maxillary palp and right portion of head in frontal view, numbers indicate maxillary palp article; B. Labrum and labial palps in dorsally inclined frontal view; C. Right foretibia in frontal view; D. Left fore- and hindwing in dorsal view, arrows indicate where the vein CuP and A1 meet the posterior forewing margin; E. Details of paraproct and clunium from lateral view; F. Details of ovipositor from ventrolateral view. Abbreviations: clu = clunium, dov = dorsal valve, epp = epiproct,. exv = external valve, lap = labial palp, lb = labrum, md = mandible, pap = paraproct, pcl = postclypeus, vev = ventral valve.

Figure 11. 

A–J. 3D-reconstruction of ‡Amphientomum knorrei sp. nov. A. Labrum in anterior view; B. Labrum in posterior view; C. Mandibles in anterior view; D. Mandibles in posterior view; E. Maxillary palps, top left palp, bottom right palp, numbers indicate palp article; F. Laciniae in anterior view; G. Sitophore; H. Salivary sclerites in anterior (right) and posterior (left) view; I. Tentorium in dorsal view; J. Labium in anterior (left) and posterior (right) view. Abbreviations: asmd = anterior socket of mandible, asas = apodeme of salivary sclerite, ata = anterior tentorial arm, ct = corpotentorium, dta = dorsal tentorial arm, eptf = epipharyngeal transverse fold, gl = glossae, inc1/2 = incisivi 1 and 2, lap1/2 = labial palp article 1 and 2, lfsas = longitudinal furrow of salivary sclerite, mdce = mandibular cutting edge, mesit = median extension of sitophore, mo = mola, mor = mortar, mot = molar tooth, pcmd = posterior condyle of mandible, pgl = paraglossa, pmdt = proximal mandibular tooth, pta = posterior tentorial arm.

Head appendages. The lobe-shaped labrum (Figs 6A, 7A, B, 10B, 11A, B, lb) is approximately 2-times as wide as long and covered with long setae (likely sensilla) (Fig. 10B). It is narrower at its base and apex and widest at about midlength. A median notch is missing, and the distal margin evenly rounded. The labral nodes are absent and epipharyngeal sensilla are not visible. A median transverse epipharyngeal fold (Fig. 11B, eptf) is present on the middle region of the epipharynx. The antennal insertions are located in a fovea (Fig. 7A, B, gef), which partly separates the genal region from the frontal region. The genal area is almost twice as long as the frontal area. The internal genal ridge below the fovea is straight (Figs 8A, 9, ger) and increases in thickness posteriorly. It starts shortly behind the posterior end of the ridge enclosing the antennal foramen and ends at the posterior genal region. It corresponds externally with the straight genal sulcus (Fig. 7A, B, ges). The antennae have 15 articles. The barrel-shaped scape and pedicel are approximately as long as wide. All flagellomeres display a secondary annulation (Fig. 5F). The last flagellomere is relatively short and pointed apically. The entire flagellum is very thin and thread-like, with the flagellomeres approximately 1/3 as wide as the pedicellus. The setae on the flagellum are long and thin, slightly thicker and longer on the lateral surface compared to the medial side. The basal portion of the flagellomeres is only faintly differentiated (Fig. 5F), and a proper collar is not developed (see Seeger 1975). The mandibles (Figs 7A, B, 9, 11C, D, md) are subtriangular with similar lengths of the mesal and lateral edges. They are not elongated and of the “outer margin rounded, and posterior margin not hollowed” type (Yoshizawa 2002). The lateral edge is convex over its entire length. The molar region (Fig. 11C, D, mo) is asymmetric, with a distal molar tooth (Fig. 11C, D, mot) on the left mandible. The right mandible has a proximal tooth-like extension (Fig. 11C, D, pmdt). The inner mandibular rim has no distinct features differentiating it from mandibles of other psocids. It is thickest on its median side and becomes narrower laterad. The lateral side of the mandibular rim between the posterior condyle (Fig. 11C, D, pcmd) and anterior socket (Fig. 11C, D, asmd) (primary and secondary mandibular joints) widens. Two apical teeth (incisivi) are present, the apical one (Fig. 11C, D, inc1) longer and wider than the subapical one (Fig. 11D, inc2). Slightly proximad of the incisivi a blade-like projection is present, a convex cutting edge (Fig. 11C, D, mdce). A postmola is not discernible. The apodeme of the mandibular adductor (Fig. 9, amdad), at least partially preserved, inserts on the medial base of mandible. The maxilla lacks a cardo. The stipes (Fig. 7B, st) is oval and represents the main body of the maxilla, together with the apical palpifer (Fig. 7B, ppf). The galeae (Fig. 7A, B, ga) are relatively flat and located between the mandibular concavity anteriorly and the hypopharynx posteriorly (visible in µCT-scan). The tip of the lacinia (Figs 11F, 12I, lc) is long and bears several rounded denticles. It is bent laterad apically. The inner tine is short and bent slightly inwards distally. The outer tine is distinctly longer and higher. The lacinial gland is not preserved or not present. The maxillary palps (Figs 6A, 11E, mxp) consist of four articles. The second article is the longest, ca. 1.3 times as long as the fourth and ca. 2 times as long as the third. The first article is extremely short and only ¼ as long as the third. Several long setae (likely sensilla) are located on each palpomere except for the glabrous first one. The second maxillary palpomere lacks a conical sensillum. The fourth palpomere is conical and has a rounded apex. The hypopharynx (Fig. 9, hy) is equipped with the anterior sitophore (Figs 9, 11G, sit) and the paired posterior salivary sclerites (Figs 9, 11H, sas). A triangular median extension of the sitophore (Fig. 11G, mesit) is present proximad the mortar, which is (Fig. 11G, mor) is oval and embedded in the sitophore like in a sclerotized block. The oral arms of the sitophore are present but indistinct in the µCT-scan. The paired salivary sclerites are lateral elements of the posterior hypopharynx, ovoid and bowl-shaped. They bear a long apodeme (Fig. 11H, asas) which is long and curved inwards at its internalmost apex. A furrow runs longitudinally (Fig. 11H, lfsas) across each salivary sclerite. The tubular filaments between the sitophore and salivary sclerites are not visible (a resolution of 2 µm is not sufficient for visualizing the very thin tubular filaments, which have a diameter of ca. 3 µm in a large psocid (von Kéler 1966) and connect the longitudinal furrow of the posterior salivary sclerites with the anterior hypopharyngeal mortar), but are likely developed, as the water-vapor absorption apparatus functionally depends on their presence. The labium is composed of a thin-walled and weakly sclerotized postmentum (Fig. 9, pom) and a thicker-walled prementum (Fig. 9, prm). A median furrow separates symmetrical premental halves (see Fig. 11J). The labial palps (Fig. 11J, lap) have two articles. Palpomere 1 (Fig. 11, lap1) is short and narrow, and palpomere 2 (Fig. 11, lap2) plate-like, large and rounded, and displays a darkly pigmented field. The second palpomere bears many long setae (likely sensilla), that are concentrated on the margin. The short and rounded paraglossae (Figs 6A, 11J, pgl) are inserted between the palps. The glossae (Figs 6A, 11J, gl) are probably represented by lobe-shaped structures, almost fused medially, with only a faint medial dividing line. Remnants of soft tissue are visible in the head, which are likely vestiges of the central nervous system, retinulae and possibly the mandibular adductor muscle, as well as other cephalic muscles.

Thorax. The cervical region is not exposed. The laterocervical sclerite is indistinctly visible as a thin bar-shaped sclerite, but scarcely discernible from the cervical membrane in the renders. The prothorax is strongly reduced. The pronotum (Fig. 8A, B, prn) is very short and bar-shaped, and the propleurae (Appendix 1: Fig. A3) are continuous with it laterally. The relatively large episternum is located dorsad the small preepisternum (Appendix 1: Fig. A3) and separated from it by an external furrow (Appendix 1: Fig. A3). The mesothorax exceeds the height of the pronotum (Figs 6B, 7A, B, 8A, B). The mesonotum (Figs 6B, 7A, B, 9A, B) is strongly enlarged and dorsally densely covered with scales (Figs 5A, 6B). A prophragma is not developed or extremely reduced. The mesonotum consists of an anterior semicircular part of the scutum, larger paired lateral scutal lobes, and a posterior triangular scutellum (Fig. 6B). The anterior scutal portion is separated from the lateral lobes by the lateral parapsidial sulci (Fig. 6B), which correspond with internal parapsidial ridges (Fig. 8A, B, parr). The postnotum is located posteroventrad the scutellum as a bar-shaped short sclerite (Fig. 6B). The mesophragma (Fig. 8A, B, msp) is wide and strongly developed. The scutoscutellar suture (Fig. 6B) is present, albeit somewhat weakly developed. The metathorax is distinctly shorter than the mesothorax. The anterior and lateral lobes of the scutum are not separated by an external furrow, whereas a distinct scutoscutellar line delimits the small, rounded scutellum. The metaphragma (Fig. 8A, B, mtp) is wide but smaller than the mesophragma. As the pleural elements of the specimen appear asymmetric on both sides and as there are many artifacts in the 3D-model, we will not describe this thoracic region in detail. The external sternal elements of each thoracic segment are not discernible from surrounding membranous regions. The profurcae (Fig. 8A, B, prf) are only indistinctly recognizable, whereas the meso- and metafurcae (Fig. 8A, B, msf, mtf) are distinctly visible as distally widened and flattened arms. Spinae of the meso- and metathorax are absent. The three pairs of coxae are adjacent medially. The profemur bears at least 27 ventral spines (Fig. 10C). The protibia bears one, and the mesotibia three apical spurs. The metatibia displays three short and three long apical spurs. All tarsi are 3-segmented. Metatarsomere 1 bears 24 ctenidiobothria (Fig. 5E). Tarsomere 1 of the foreleg and hindleg are almost 3 times as long as the respective tarsomeres 2 and 3 combined. The very long metarsomere 1 reaches ca. ¾ of the length of the metatibia. Mesotarsomere 1 is approximately twice as long as mesotarsomeres 2 and 3 combined. Two apical ventral spurs are inserted on tarsomeres 1 and 2 of each pair of legs. The symmetrical claws are equipped with a single small preapical tooth (Fig. 5D) and several ventral microtrichia proximad this structure. Pulvilli are absent. The mirror and rasp substructures of the Pearman’s organ are absent. A distinct ball-shaped cuticular projection (Fig. 12A, B, hcp) on the inner side of the left metacoxa is visible, fitting with a cup-shaped emargination (Fig. 12A, B, hce) on the inner side of the right metacoxa. The legs, especially the femora and tibiae, are densely covered with scales. Several closely placed somewhat irregular rings of these surface structures are inserted on the metafemur (Fig. 5C).

Figure 12. 

A. Photography of ‡Amphientomum knorrei sp. nov., posterior view of hindcoxae, arrows indicate the interlocking mechanism; B. 3D-reconstruction of ‡Amphientomum knorrei sp. nov., posterior view of hindcoxae. Abbreviations: co = coxa, fe = femur, hce = hindcoxal emargination, hcp = hindcoxal projection, tr = trochanter.

Forewing. Wing with three types of scales. First type long, parallel-sided, straight and with a straight apex (Fig. 5H). Second type long (slightly to distinctly shorter than type one), parallel-sided to subparallel and straight, emarginate with a median notch (Fig. 5H). Third type short, broad, parallel-sided from 2/5 to apex of scale, and converging in the basal 1/5, with a straight and finely frayed apex (Fig. 5G). The wing scales display a longitudinal striation except for type I where this is not visible. The scale patterning is very distinct, with an increased density at the wing base, differentiating it from related species (Figs 5A, B). The proximal Sc vein is very short and ends freely in the wing membrane. A line of dark scales follows approximately this vein. R1 merges at 2/3 of the wing length with the anterior margin. A short and anteriorly bent distal Sc vein closes the pterostigma. This triangular cell displays a strongly acute angle between Sc and R1 and is wide (600 µm) but very low (110 µm). The base of Rs forms an obtuse angle with the distal portion of this vein. The basal vein of Rs is almost transparent, and dorsally bears a patch of dark scales. The veins R2+3 and R4+5 are convex almost over their whole length, and M1 is curved distally. M2 is almost straight. M3 is concave distally. The origins of all three M veins are placed close to each other, almost forming a fork. The specimen displays a slight asymmetry in the base of the three M veins. On the right forewing, they originate from a common stem, while M1+M2 are connected in left one but both separated from the base of M3. A conspicuous acuminate lobe is present between M1 and M2, and a short cross vein between Rs and M (90 µm). The areola postica is relatively wide and low and forms a triangle with an acute angle between CuA1 and CuA2. CuP and A1 join the posterior wing margin at a distance from each other (Fig. 10D). The course of the very faint vein A1 is almost invisible due to the coupling of the fore- and hindwing on both sides. The vein A2 is indistinct.

Hindwing. Type I and II scales are present (Fig. 5H). No closed cell is present in the hindwing (Figs 5A, B). R1 and CuA are ending at approximately 2/3 of the total wing length, the former on the anterior margin and the latter on the posterior margin. Only one M vein is present. The common veins R2+3 and R4+5 are slightly shorter than half the length of M. R2+3 end anteriorly on the margin in the last 1/5 of the wing length. R4+5 ends almost directly on the wing apex, and M almost at the same length as R2+3 but on the posterior margin. Rs is bent anteriorly where it forms a cross vein with R1 in other Amphientomum species, but any trace of this cross vein is lacking. CuA is curved at its distal end. The distance between CuA and CuP is approximately equivalent with the length of Rs. A1 is curved and ends on the basal posterior wing margin. The margin of the apical half is covered with long scales and setae, the latter more densely anteriorly.

Abdomen. The abdomen is strongly bent towards the thorax (Figs 5A, B, 7A, B). The external segmentation of the abdomen is only partially visible, as some segmental borders are very faint or deformed as an artefact. However, it seems to follow the general pattern in Psocodea (Badonnel 1934) without any conspicuous modifications. The clunium (Fig. 10E, clu), the epiproct (Figs 8B, 10E, epp) and the paraproct (Figs 8B, 10E, pap) are unmodified, the latter covered with long setae and bearing an indistinct sensorium. The apex of the subgenital plate is simple and covered by long setae. The subgenital plate largely covers the ovipositor valves, thus only the tips are exposed (Figs 5B, 6C, 7C). The external valve (Fig. 10F, exv) is bilobed, the dorsal portion wider but not as long as the ventral portion, which is pointed apically. The dorsal valve (Figs 7C, 10F, dov) is almost tubular and apically rounded. The ventral valve (Fig. 10F, vev) is barely discernible but present as an elongated tube.


Die Art und Weise der Lagerung und Erhaltung der Stücke im Bernstein erlaubt den Schluß, daß diese Art wesentlich wilder und beweglicher gewesen sei als die übrigen Psocen, dabei aber zugleich weniger derb gebaut. Daß bei den sichtlich starken Anstrengungen der Thiere, dem Harz zu entgehen, das Schuppenkleid oft stark abgerieben wurde, ist leicht begreiflich und durch mitunter massenhaft danebenliegende Schuppen bewiesen. Aber auch die Endglieder der Fühler sind mitunter beim Vordrängen des Thieres abgetrennt, und die obere Membran der Flügel ist zuweilen von der offenbar fester dem Harz anhängenden unteren Membran getrennt, und beim Vordrängen des Thieres in regelmäßige kleine Querfalten gebracht.” – Hermann Hagen’s (1882) commentary about the preservation of Amphientomum specimens in Baltic amber.

Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov. (Troctomorpha: Amphientometae: Amphientomidae) represents the first record of this family and genus in East African copal (14C date: ~390 ± 13 years old) and may still be extant in East Africa. The genus Amphientomum is known from the lowermost Eocene amber of Oise in France and is at least 56.0–47.8 Mya (Nel et al. 2005) old. In total, 20 species are described including the new one presented here (Table 5). Today they occur in countries of Western (Ivory Coast, Nigeria), Central (Angola, Republic of the Congo) and Eastern Africa (Madagascar, Tanzania) (Lienhard 2016; Johnson et al. 2023), and one additional species is described from China (Li 1999, 2002). Four species are known from the fossil record, two, as previously listed, were described by Enderlein (1905), and one by Pictet (1854) from Baltic amber. Additionally, one species was described from French Eocene Oise amber by Nel et al. (2005). The subfossil described here is a female, as the subgenital plate and the apical tips of the valvulae are visible. It differs from all other described species of Amphientomum by its characteristic forewing scale pattern.

Only one species has been assigned to Amphientomum outside of Africa and Eurasia, Am. indentatum Turner, 1975, from an extant population in Jamaica. However, this species is definitely misplaced, as several features of it are not compatible with the currently accepted diagnostic character repertoire of Amphientomum (see Taylor 2013 for an identification key of the genera of Amphientomidae), i.e., the lateral ocelli are widely spaced and close to the compound eyes, and the hind wing vein R1 does not reach the wing margin. Given these characters, the species in fact matches with Lithoseopsis Mockford, 1993 (Mockford 1993; Taylor 2013). Taylor (2013) proposed a smoothly rounded distal forewing margin as a diagnostic character of this genus. In contrast, Am. indentatum displays a characteristic indentation at the tip of the forewing, as reflected by the species name. However, the tips are not acuminate as in ‡Am. knorrei sp. nov., similar to other species in Lithoseopsis (see Taylor 2013). Based on these observations, we propose a new taxonomic combination: Lithoseopsis indentatum (Turner, 1975) comb. nov. By excluding L. indentatum from the genus Amphientomum, this is now restricted to the Afrotropics and Palearctic (see Table 5). The number of described species of Lithoseopsis is hereby increased to 12 (Johnson et al. 2023). Broadhead and Wolda (1985) mentioned the occurrence of three different species of the subgenus Amphientomum (Palaeoseopsis) in Panama. However, they remain undescribed and no details besides the collecting information are known. It is conceivable that these specimens do not belong to Amphientomum, similar to the previously stated case.

As the basal section of Rs is absent in the hindwing of ‡Am. knorrei sp. nov. (Fig. 13A), the species can be assigned to the subgenus Amphientomum (Palaeoseopsis) in the system of Roesler (1944). The shape of scales is arguably not a good diagnostic feature, as several types of scale shapes can occur in a single specimen. Emarginate scales are present in ‡Am. knorrei sp. nov. (type II scales, Fig. 5H), a diagnostic character of the subgenus Am. (Amphientomum) after Roesler (1944), but there are also scales with an evenly truncated (type I scales, Fig. 5H) or a frayed (type III scales, Fig. 5G) apical edge, a diagnostic criterium for Am. (Palaeoseopsis). On the other hand, Enderlein (1911) introduced evenly truncated scales as diagnostic character for Am. (Amphientomum), while scales with a median notch are characteristic for Am. (Palaeoseopsis). It is likely that Roesler (1944, p. 138) was mistaken in the characterization of both subgenera. As the polarity of the presence or absence of the basal section of Rs in the hindwing is unknown, the subgenus Am. (Palaeoseopsis) is possibly not monophyletic. All species except for †Am. leptolepis and †Am. paradoxum, both described from Baltic amber, have a reduced basal section of Rs in the hindwing (Table 5). Several species, such as Am. loebli and Am. pauliani (Table 5), also have a vestigial basal section of Rs, but it is never fused with R1. Given these problematic definitions, we synonymize Palaeoseopsis under Amphientomum syn. nov. and consequently remove the subgeneric rank from Amphientomum pending future study.

Figure 13. 

A–Q. Schematized drawings of all available laciniae of Amphientomum species from the literature and of ‡Amphientomum knorrei sp. nov. (Amphientomidae: Amphientominae) preserved in piece PMJ Pa 5809. The laciniae are not up to scale, and the orientation of the lacinia was flipped at 180° for C, E, H, J–L, N–P from the original drawings, only the apical portions of the laciniae are shown. A. Am. acuminatum, male; B. Am. aelleni, nymph; C. Am. annulicorne, female; D. Am. annulitibia; E. Am. dimorphum, sex not specified; F. Am. dimorphum, sex not specified; G. Am. flexuosum, female; H. Am. hieroglyphicum; I.Am. knorrei sp. nov., female, redrawn after 3D render; J. Am. loebli, female, K. Am. mimulum, sex not specified; L. Am. montanum, female; M. Am. pauliani, male; N. Am. punctatum, male; O. Am. simile, female; P. A. simile, female; Q. Am. striaticeps, female. Figures modified from the following: A, C, E, F, H, K, L, N, O, P, Q after Badonnel (1967); D after Smithers (1999); B after Badonnel (1959); G after Badonnel (1955); J after Badonnel (1979); M after Smithers (1964).

Several characters of ‡Am. knorrei sp. nov. resemble features of Am. acuminatum, like the shape of the apex of the lacinia (see Fig. 12 for comparison of all available Amphientomum species), the apical lobe of the forewing (see Figs 13, 14 for comparison of all available Amphientomum species), as well as the claw with a single preapical tooth. Consequently, this species from Madagascar (Smithers 1964; Badonnel 1967) might be closely related with ‡Am. knorrei sp. nov. It differs from it by smaller size (body length = 2.1 mm, forewing length = 2.75 mm), the lower number of ctenidiobothria on the first tarsomere of the hindleg (21–22), the scale pattern on the forewings, and also the facial markings. As the origin of our piece of resin with the psocid inclusion is not fully clarified, the geographical distribution of ‡Am. knorrei sp. nov. remains uncertain. That the specimen is enclosed in East African copal imported to Germany during colonial times is suggested by several syninclusions, for instance the Dorylus in our present collection. The countries of origin of such pieces of resin are Tanzania, Mozambique, and Madagascar (Delclòs Martínez et al. 2020). It is therefore likely that Am. acuminatum and ‡Am. knorrei sp. nov. have a common distribution in East Africa, while the exact distribution of both species is still unclear.

Figure 14. 

A–I. Schematized drawings of all available fore- and hindwings of Amphientomum species from the literature and of ‡Amphientomum knorrei sp. nov. (Amphientomidae: Amphientominae) preserved in piece PMJ Pa 5809. The same scale bar was used for B–I. A.Am. knorrei sp. nov., female; B.Am. colpolepis; C.Am. paradoxum, female; D.Am. parisiense; E. Am. acuminatum; F. Am. annulicorne, female; G. Am. annulitibia, male; H. Am. dimorphum, female; I. Am. dimorphum, male. Figures modified from the following: B, C after Enderlein (1911); D after Nel et al. (2005); E after Smithers (1964); F, H, I after Badonnel (1967); G after Smithers (1999).

Finally, an unsolved nomenclatorial issue concerning Amphientomum ectostriolate Li, 1999 requires clarification. In the Psocodea Species File (Johnson et al. 2023, date: 2023 August 17) the year of publication for this species is incorrectly listed as Am. ectostriolate Li, 2002 and the species Am. ectostriolatis Li, 1999 mistakenly listed as a valid taxon. We contend that the name should be Am. ectostriolate Li, 1999 based on the following reasoning: (1) The protonym, Am. ectostriolatis, was established and illustrated in the monograph on the Chinese Psocoptera (p. 199) by Li (2002); (2) the spelling was later emended by Lienhard (2003) to Am. ectostriolate Li, 1999, justifiably so by Articles 19 and 34 of the ICZN (1999), with this emendation considered to be the original spelling by section 32.2; and (3) the name Amphientomum ectostriolatum Li, 2002 should be considered an unjustified emendation by Article 33, as the author spelled the name this way in the figure legend and twice in the text, indicating an intended name change, hence this name is available but should be a junior synonym of Am. ectostriolate syn. nov.

Amphientomum ectostriolate Li, 1999

Am. ectostriolatis Li, 1999; original spelling; justifiably emended to ectostriolate by Lienhard, 2003: p. 699.

= Am. ectostriolatum Li, 2002 [available unjustified emendation by Li, 2002], syn. nov.

Identification key for all species of Amphientomum Pictet, 1854

The present key is modified after Badonnel (1967) using information from Enderlein (1911), Badonnel (1955, 1979), Smithers (1964, 1999), Li (1999, 2002), and Nel et al. (2005). Note that the species Amphientomum aelleni Badonnel, 1959 is excluded from the key as only the nymphal stage is described. This species, however, can be identified using an illustration of the unique coloration pattern of the head (Badonnel 1959, p. 763, fig. 1).

1 (A) Species only known from the fossil record. (B) Rs in forewing at a right angle to R1 2
(A) Extant species or subfossil. (B) Rs in forewing at an obtuse angle (proximal angle) or almost a right angle to R1 5
2 (A) In Eocene French Oise amber. (B) Basal section of Sc in forewing long, more than half the length of R1 Am. parisiense Nel, Prokop, De Ploeg & Millet, 2005
(A) In Eocene Baltic amber. (B) Basal section of Sc in forewing short, less than half the length of R1 3
3 (A) Scales with an apicomedial notch. (B) Basal section of Rs missing in hindwing Am. colpolepis Enderlein, 1905
(A) Scales apically straight. (B) Basal section of Rs present in hindwing 4
4 (A) Scales short and broad, tapering proximally. (B) Tarsomere 1 of hindleg with 29–34 ctenidiobothria Am. paradoxum Pictet, 1854
(A) Scales long and narrow, parallel-sided over entire length. (B) Tarsomere 1 of hindleg with 36 ctenidiobothria Am. leptolepis Enderlein, 1905
5(1) (A) Rs in forewing almost at right angle to R1. (B) Distributed in China Am. ectostriolate Li, 1999
(A) Angle between Rs and R1 in forewing distinctly obtuse (proximal angle). (B) Recorded from Africa 6
6 (A) Proximal half of antennal flagellum with 4 white rings separated by three black-brown rings. (B) Additionally: proximal 2/3 of femora dark brown; tibiae with three dark brown rings; forewings very wide in relation to their length, their posterior margin strongly arched in the apical half Am. annulicorne Badonnel, 1967
(A) Antennal flagellum almost uniformly brown, without alternating white and dark rings. (B) Other characters variable 7
7 (A) Compound eyes elevated or apparently raised above dorsal margin of vertex (frontal view) 8
(A) Compound eyes on same level as dorsal margin of vertex (frontal view) 10
8 (A) Dorsal margin of vertex straight (frontal view). (B) In frontal view, lateral sides of dorsal margin curved downwards, so that compound eyes appear elevated above the rest of the dorsal margin Am. loebli (Badonnel, 1979)
(A) Dorsal edge of vertex distinctly concave (frontal view). (B) In frontal view, compound eyes thus strongly prominent laterally 9
9 (A) Legs pale. (B) Proximal halves of fore- and midfemora brown but apices pale; outer margin of proximal halves pale like distal half. (C) Hindfemora with single brown median spot. (D) Tibiae pale, with faint rings. (E) Maxillary palps pale brown, darkening distally. (F) Larger laterodorsal spots on vertex not composed of small dots Am. montanum Badonnel, 1967
(A) Legs dark. (B) Proximal halves of all femora with brown apices; remaining areas yellow. (D) Tibiae with three distinct brown rings. (E) Maxillary palps dark brown. (F) Larger laterodorsal spots on vertex formed by small dots Am. dimorphum Badonnel, 1967
10 (A) Vertex and frons divided transversely by three or four parallel brown stripes, which extend across compound eyes. (B) Legs pale with few smaller brown patches 11
(A) No transverse brown stripes on head. (B) Legs brown or pale with extensive brown bands 12
11 (A) Forewing strongly convex at level of areola postica. (B) Areola postica smaller, shorter than the next distal section of vein M. (C) Claws with one row of small spines proximad the distalmost preapical tooth Am. striaticeps Badonnel, 1967
(A) Forewing weakly convex at level of areola postica. (B) Areola postica larger, longer than the next distal section of vein M. (C) Claws with one row of distinct teeth proximad distalmost preapical tooth Am. simile Badonnel, 1967
12 (A) Forewing almost uniformly brown, apical third paler. (B) Body color chocolate brown 13
(A) Distinct patterns of contrasting light and dark patches on forewing. (B) Body color variable 14
13 (A) Forewing rounded apically. (B) Forewing posterior margin only slightly flexed distally. (C) Head brown with some diffuse spotting between compound eyes and close to ocelli. (D) Femora uniformly dark brown; scales with double striation. (E) Common base of parameres wide Am. pauliani Smithers, 1964
(A) Forewing apex pointed. (B) Forewing posterior margin distinctly flexuous. (C) Head uniquely patterned with series of darker dots with various size and horizontal stripes. (D) Femora dark brown on proximal 2/3 or 3/4, with yellow brown apex. (E) Common base of parameres very narrow Am. punctatum Badonnel, 1967
14 M2 and M3 in forewing strongly curved posteriad at their apical third 15
M2 and M3 in forewing parallel or only slightly curved 16
15 (A) Frontal area of head crossed by three distinctive transverse chocolate brown bands. (B) Anterior end of phallosome frame close to basal plate more rounded Am. flexuosum Badonnel, 1955
(A) Head without distinctive transverse brown bands. (B) Anterior phallosomal curvature variable Am. annulitibia Smithers, 1999
16 (A) Hindwing R1 interrupted shortly before costa. (B) Forewing without apical lobe. (C) Forewings with unique pattern: anterior and apical margin with several vertical stripes and patches of scales, and basal half almost completely covered with scales. (D) Tibiae uniformly brown Am. mimulum Badonnel, 1967
(A) Hindwing R1 reaches costa. (B) Forewing with apical lobe. (C) Forewings without this unique pattern. (D) Tibiae with rings of brown scales 17
17 (A) Forewing without large brown patch covering most of anal area. (B) Forewing in its apical 1/3 anteriorly with crescent shaped white patch bordered by brown area. (C) Femora not completely brown. (D) Common base of parameres wide and short Am. hieroglyphicum Badonnel, 1967
(A) Forewing with broad zone of dark scales from distal 1/3 of M + Cu to edge of anal area. (B) Forewing without crescent shaped white patch and brown border. (C) Femora completely brown. (D) Common base of parameres wide and fairly long (unknown for Am. knorrei, as no male described!) 18
18 (A) Head yellowish brown. (B) Vertex with irregular vertical lines parallel to compound eyes and coronal sulcus. (C) Metabasitarsus with 21–22 ctenidiobothria. (D) Anteroproximal region of forewing with or without sparse vestiture of scales Am. acuminatum Smithers, 1964
(A) Head dark brown. (B) Vertex without irregular vertical lines. (C) Metabasitarsus with 24 ctenidiobothria. (D) Anteroproximal region of forewing densely covered with dark brown scales Am. knorrei Weingardt, Bock & Boudinot sp. nov. Further considerations of Amphientomum

Several hypotheses on relationships between species of Amphientomum have been proposed. According to Badonnel (1979), Am. flexuosum and Am. loebli are sibling species (= espèce voisine), but differ in details of coloration, the reduction of the basal section of Rs in the forewing of Am. loebli, and by the presence of a sclerite of the subgenital plate in this species, which is lacking in Am. flexuosum (Badonnel 1979). Moreover, both species differ in size and the number of femoral spines (Badonnel 1979), but whether these differences are stable and statistically significant is presently unclear. Both species occur in West Africa and western Central Africa (Angola, Ivory Coast, Nigeria). Additionally, Smithers (1999) proposed that Am. annulitibia is likely closely related to Am. flexuosum, but noted that it differs in the shape of the anterior margin of the phallosome and in the coloration of the head.

There are few studies on the ecology and faunistics of the East African Psocodea, including for instance the family Amphientomidae (Broadhead and Richards 1982; Georgiev 2022a). One species whose description is based on a single nymph from a Congolese cave might indicate weak troglophilic tendencies (Badonnel 1959). As Badonnel (1959) already discussed, a detailed study on the morphology of nymphal stages of Amphientomidae is needed before the specimen can be reliably placed in a genus. Several genera and the subfamily Tineomorphinae can nevertheless be excluded from the list of potential taxa based on the presence of profemoral spines and the shape of the lacinia (Badonnel 1959), while the genus Amphientomum seems to be the most likely taxon based on the few described characters that the nymph shares with species of Amphientomum. Several species of the genus are known to be attracted by light traps (Badonnel 1979; Smithers 1999).

A character of special interest is the coxal interlocking device described here for the new species (Fig. 15A, B). It consists of a hemispherical outgrowth on the right metacoxa, which fits into a corresponding cavity on the opposite side. A similar device was described by Pearman (1935) for the amphientomine genera Syllysis and Nephax, but never before for a species of Amphientomum. It is conceivable that the interlocking device is part of a jumping mechanism, but there are no observational data for amphientomids that would support this hypothesis. Interestingly, another interlocking device has been described for species of Lepidopsocidae, in this case on the mesocoxae but with a similar arrangement of a hemispherical protuberance on the right and a cavity on the left side, and involvement in jumping was also suggested in this case (Menon 1938; Ramesh et al. 2020). The occurrence of these devices on different segments represents a remarkable case of parallel evolution in the Psocodea. The evolutionary background still requires clarification.

Figure 15. 

A–L. Schematized drawings of all available fore- and hindwings of Amphientomum species from the literature. The same scale bar was used for A–L. A. Am. ectostriolate, B. Am. flexuosum; C. Am. hieroglyphicum, female; D. Am. hieroglyphicum, male; E. Am. loebli, female; F. Am. mimulum, male; G. Am. montanum, female; H. Am. pauliani; I. Am. punctatum, male; J. Am. punctatum, female; K. Am. simile, female; L. Am. striaticeps, female. Figures modified from the following: A after Li (2002); B after Badonnel (1955); C, D, F, G, I, J, K, L after Badonnel (1967); E after Badonnel (1979); H after Smithers (1964).

A candidate homolog for the coxal interlocking devise is the Pearman’s organ, a unique structure of Psocodea, which consists of a mirror and rasp on the inner side of the metacoxae in most psocids (Mockford 2018). It can be missing (e.g., Pachytroctidae, Sphaeropsocidae, and likely in Liposcelididae, where the metacoxae are distinctly separated; Yoshizawa and Lienhard 2010; Mockford 2018) or certain substructures can be reduced (e.g., Amphientomidae with only the mirror part; Weidner 1972; but see discussion above and Mockford 1993 for a different view on the presence of the rasp in the family). We were unable to observe any rasping structures on the metacoxae in ‡Am. knorrei sp. nov. It is possible that the structure was in fact present but is indistinct due to artifacts and the quality of preservation of our specimen. As the mirror was also not visible in the SR-µ-CT scan and photographs or using light microscopy (maximal resolution 200 ×), it appears plausible that this interlocking device represents a modification of the Pearman’s organ, especially due to the functional requirement of intercoxal contact. Pearman (1935) proposed the same hypothesis on the origin of this device in other Amphientomidae. Smithers (1999) described the “tympanum” of the metacoxae of Am. annulitibia Smithers, 1999, with a thick and strongly raised edge but without an illustration. Nevertheless, it is conceivable that a similar structure is present in this species (described as inconspicuous by Smithers 1999), and that the device is more strongly developed in ‡Am. knorrei sp. nov. In any case, the device described here differs from the mesocoxal interlocking mechanism observed in Lepidopsocidae, which probably represents a non-homologous neoformation.

The lack of a robust phylogeny of Amphientomidae impedes the systematic placement of new species. As many genera are only defined by diagnostic characters and not apomorphies (e.g., Taylor 2013), the possibility of non-monophyly of these groups cannot be excluded and paraphyly may even be widespread in the family. It is therefore important for future research to establish a robust phylogeny of amphientomids, based on molecular data and morphological apomorphies. Badonnel (1967) explicitly mentioned that the use of different characters would lead to different systematic placements of his newly described species. This underlines the lack of morphological support for groupings in the family. Badonnel also commented on the minimal variability of the genitalia in Amphientomum, as only the basal common shaft of the parameres and the spermapore sclerite are suitable for diagnostic purposes. Mockford (2018) supported this observation, stating that external genitalia of both sexes are uniform throughout the entire amphientomids, with a y-shaped phallosome and three ovipositor valves, with a bilobed external valve (V3) fused over a part of its length with the dorsal valve (V2). The shape of the forewings can also be used as a diagnostic feature (Badonnel 1967), but sexually dimorphic wing shapes in a single species have to be considered (Badonnel 1967). The shape of the lacinia is an important diagnostic feature (Badonnel 1967) and is displayed together with the wing venation in Figs 1315 for all species of Amphientomum with available data. As a phylogenetic analysis and a detailed study of type material would be beyond the scope of this study, we refrain from providing an updated diagnosis of Amphientomum or the subgenus Amphientomum (Palaeoseopsis). However, our study is a first step towards a phylogenetic investigation of the genus. Additional observations and remarks for Psocodea in the PMJ Pa collection

A single apterous liposcelidid trapped in the large piece of resin PMJ Pa 5827 together with many other syninclusions is slightly deformed and almost transparent (Fig. 16C). It is a nymph, as only 8 antennomeres are visible, and the specimen is only ca. 0.9 mm long. As no external metafemoral tubercle is visible, it is likely that the single specimen belongs to the subfamily Embidopsocinae. To assign it to a genus of this subfamily and to make sure that the tubercle on the metafemur is indeed absent, further trimming and cutting of the amber piece would be necessary for higher magnification. However, as many syninclusions could be affected by this we refrained from further processing. As the specimen is miniscule, we could not observe other taxonomically relevant characters (Lienhard 1991), for instance the number of tarsomeres. Even though we do not assign the specimen to a genus, we could verify that the last maxillary palpomere is conical, and not enlarged as in Belapha Enderlein, 1917, Belaphopsocus Badonnel, 1955, Belaphotroctes Roesler, 1943 or Troctulus Badonnel, 1955 (Lienhard 1991). This makes a placement in these genera unlikely.

Figure 16. 

A, B. Photography of Archipsocidae gen. et sp. indet. preserved in piece PMJ Pa 5825. C. Photography of Liposcelididae gen. et sp. indet. Preserved in piece PMJ Pa 5827. A. Habitus in dorsal view; B. Habitus in ventral view; C. Habitus in ventral view, arrow indicates right hindfemur.

Additionally, one single macropterous specimen of the family Archipsocidae is present in the resin piece PMJ Pa 5825 (see Figs 16A, B, 17A, B, 18A, B, Appendix 1: Fig. A4). The presence of large wings indicates that this individual is a female (Mockford 1993). As the genital region is deformed and blocked by a large air bubble, it is unclear whether ovipositor valvulae are present or not. The visible, apically flattened and very wide subgenital plate resembles the homologous structure of Archipsocopsis (Mockford 1993, fig. 248; Georgiev 2022b, fig. 30). The results of the FT-IR analysis (IAA) suggest that the resin containing the archipsocid belongs to a kauri-type (see SI: Report No 41995_17022023), a tree species today only occurring in New Zealand (Steward and Beveridge 2010). This suggests that the specimen might be part of the fauna of this country and the first possible record of the family in this region (Lienhard 2016). That the specimen belongs to the genus Archipsocopsis is tentatively suggested by the shape of the subgenital plate. As further confirmation is required, we treat it here as Archipsocidae gen. et sp. indet. We briefly characterize this specimen as follows: Female. Head large and globular, with comparatively small compound eyes. Antennae relatively short and with relatively thick flagellum. Three ocelli present but indistinct. Macropterous. Fore wings and hind wings completely developed. Tarsi with two articles. Ovipositor seemingly entirely missing. Subgenital plate wide and flattened posteriorly. Body length: 1.46 mm. Forewing length: 1.71 mm. Hindwing length: 1.45 mm.

Figure 17. 

A, B. 3D-reconstruction of Archipsocidae gen. et sp. indet. A. Habitus in frontal view; B. Habitus in lateral view.

Figure 18. 

A, B. 3D-reconstruction of Archipsocidae gen. et sp. indet. A. Habitus in dorsal view; B. Habitus in ventral view.

3.3.2. Order Hymenoptera: Subfamilial and tribal synopsis of fossil Formicidae in the PMJ Pa collection

In this section, we review the fossil record of each subfamily of ants that occurs in the Phyletisches Museum amber collection, with the exception of Formicinae, for which our review is restricted to the tribes Plagiolepidini and Camponotini. See section 3.3.1 for details about deposit and age source information. Subfamily Dorylinae Leach, 1815

Amber fossils: Identifiable to species:

A. Baltic ambers [Eocene, 37.8–33.9 Mya].

I. Genus †Procerapachys Wheeler, 1915. [Note 1].

1. †Pr. annosus Wheeler, 1915. [w, m]. [Type species of genus].

2. †Pr. favosus Wheeler, 1915. [w].

3. †Pr. sulcatus Dlussky, 2009. [w].

B. Dominican amber [Miocene, 20.4–13.8 Mya].

II. Genus Acanthostichus Mayr, 1887.

5. †A. hispaniolicus de Andrade, 1998b. [w].

III. Genus Cylindromyrmex Mayr, 1870.

6. †Cy. antillanus de Andrade, 1998a. [q].

7. †Cy. electrinus de Andrade, 1998a. [q].

8. †Cy. inopinatus de Andrade, 1998a. [q].

IV. Genus Neivamyrmex Borgmeier, 1940.

9. †N. ectopus Wilson, 1985. [w]. [see Wilson 1985b].Copal fossils: Identifiable to species:

C. East African copal [Holocene, 145 years based on our 14C analysis; < 36 Kya more generally, based on Solórzano-Kraemer et al. 2020].

V. Genus Dorylus Fabricius, 1793.

10. D. nigricans molestus (Gerstäcker, 1859). [w]. [See section 4.2.1; Fig. 3].

D. Colombian copal [Pleistocene(?); DuBois 1998].

VI. Genus Neivamyrmex Borgmeier, 1940.

11. N. iridescens Borgmeier, 1950. [w].

Note 1. After the morphological and phylogenomic revision of the Dorylinae by Borowiec (2016, 2019), the generic identities of the species attributed to †Procerapachys are uncertain. Ongoing work by multiple research groups will resolve at least some of these questions. At least one specimen in the BEBC is meaningfully identifiable as Lioponera (unpubl. data). Subfamily Dolichoderinae Forel, 1878 Genus †Yantaromyrmex Dlussky & Dubovikoff, 2013 [Note 1]

Amber fossils: Identifiable to species:

A. Baltic ambers [Eocene, 37.8–33.9 Mya].

1. †Y. constrictus (Mayr, 1868). [w].

2. †Y. geinitzi (Mayr, 1868). [w, q, m]. [Note 2].

3. †Y. intermedius Dlussky & Dubovikoff, 2013. [w].

4. †Y. mayrianum Dlussky & Dubovikoff, 2013. [w].

5. †Y. samlandicus (Wheeler, 1915). [w].

Note 1.Yantaromyrmex is an extinct genus of ants that is endemic to ambers from Baltic sources. The genus is of unknown phylogenetic affiliation with other Dolichoderinae, although it has been hypothesized to be close to the so-called “DNAPPTOFI” clade of the Leptomyrmecini (sensu, Ward et al. 2010; Boudinot et al. 2016), more specifically, as an ancestor of the clade containing Anonychomyrma and Iridomyrmex (Dlussky and Dubovikoff 2013). Addressing this hypothesis is outside the scope of the present study, so we retain the placement of this fossil in Leptomyrmecini and note explicitly that this is an uncertain and untested relationship.

Note 2. The PMJ Pa specimen identified as †Y. geinitzi (PMJ Pa 5856) was identified using the key of Dlussky and Dubovikoff (2013). Subfamily Formicinae Latreille, 1802 Tribe Plagiolepidini Forel, 1886

Amber and copal fossils: Identifiable to species:

I. Genus Lepisiota Santschi, 1926.

A. African copal [Holocene, < 36 Kya (Solórzano-Kraemer et al. 2020)].

1. †Le. cf. canescens [w]. [Note 1].

II. Genus Plagiolepis Mayr, 1861.

B. Baltic amber [Eocene, 37.8–33.9 Mya].

2. †Pl. klinsmanni Mayr, 1868. [w].

• Wheeler, 1915: 101 (m); Dlussky, 2010a: 65 (“ergatoid” q).

3. †Pl. kuenowi Mayr, 1868. [w].

= †Pl. balticus: Dlussky, 2010a: 69.

• Dlussky, 2010a: 70 (q).

4. †Pl. singularis Mayr, 1868. [q].

5. †Pl. solitaria Mayr, 1868. [m].

6. †Pl. squamifera Mayr, 1868. [w].

7. †Pl. wheeleri Dlussky, 2010. [w].

C. Rovno amber [Ukraine; Eocene, 38.0–33.9 Mya].

8. †Pl. minutissima Dlussky & Perkovsky, 2002. [m].

D. Saxonian (Bitterfeld) amber [Germany; Eocene (Priabonian), 38.0–33.9 Mya].

9. †Pl. paradoxa Dlussky, 2010. [m].

E. Sicilian amber [Italy; Oligocene, 11.6–5.3 Mya].

10. †Pl. labilis Emery, 1891. [w].

III. Genus Acropyga Roger, 1862.

F. Dominican amber [Miocene, 20.4–13.8 Mya].

11. †Acropyga glaesaria LaPolla, 2005. [q, m].

Species inquirendae:

II. Genus Plagiolepis.

G. Uncertain [Cenozoic?].

(1.) †Pl. succini André, 1895. [Note 2].

Note 1. This specimen (PMJ Pa 5807) may be the first fossil or sub-fossil Lepisiota recorded to date. The specimen is dark, has the bituberculate form of the propodeum associated with L. canescens, and lacks spines on the petiolar node. Lepisiota is also the third genus (of nine) from the Plagiolepidini to be recovered from fossil-bearing sediments, the other two being Acropyga and Plagiolepis. Ants of this tribe were formerly lumped with the Prenolepis genus group of the Lasiini (see Bolton 2003; Boudinot et al. 2022a).

Note 2. As reported by Dlussky (2010a, b), there is considerable uncertainty about the generic identity and geological origin of the fossil(s) described as †Pl. succini by André (1895). In André’s own words (paraphrased, p. 83), “despite its great size for [Plagiolepis], this species resembles [Anoplolepis] custodiens [F. Smith]”, with the following diagnostic note (also paraphrased): “but it is distinguished by its size and the thicker and less elongate antennae”. Dlussky (2010a, b) was unable to find the specimen(s) originally described by André and speculated that the taxon may be from East African copal, i.e., misidentified as Baltic amber. This species should, therefore, be continued to be considered of uncertain status until the original or additional material becomes available. Tribe Camponotini Forel, 1878

Overview. The Camponotini is a comparatively diverse tribe of Formicinae with > 1950 valid species attributed to eight extant genera (Bolton 2023), which have received revisionary attention subsequent to the major phylogenomic study of Blaimer et al. (2015) (see Ward et al. 2016; Ward and Boudinot 2021). Because this clade represents a major radiation of ants (e.g., Rafiqi et al. 2020), fossils are particularly important for understanding and modeling the tempo and mode of formicine evolution. The diversity of fossils attributed to this tribe, moreover, necessitates this overview. Prior to the present study, Camponotini contained two monotypic and valid fossil genera (†Chimaeromyrma brachycephala Dlussky, 1988, †Pseudocamponotus elkoanus Carpenter, 1930), one monotypic fossil genus that is a synonym of Camponotus Mayr, 1861 (†Palaeosminthurus juliae Pierce & Gibron, 1962), one fossil species attributed to Polyrhachis (†Po. annosus Wappler et al., 2009), and 29 valid and 5 invalid fossil species placed in Camponotus itself (Bolton 2023).

Based on our assessment of all 38 of these fossil species plus the three species attributed to the Camponotus-like form taxon †Camponotites Steinbach, 1967, we propose the following revision to the fossil record of Camponotini below. In brief, we transfer one species out of the subfamily Formicinae to Liometopum (I), we recognize one as-yet unidentified copal specimen of Camponotus (II) and one fossil species of Polyrhachis (III), we leave †Chimaeromyrma and †Pseudocamponotus incertae sedis in Camponotini (IV, VII), we transfer one Baltic fossil species from Camponotus to †Eocamponotus gen. nov. (V), we revive †Palaeosminthurus and consider it unidentifiable while transferring it out of Camponotini as incertae sedis in Formicinae (VI), and finally, we transfer 29 fossil species from Camponotus to the form genus †Camponotites, which we treat as a catch-all that is incertae sedis in Camponotini (VIII). We also provide detailed annotations for our synopsis of fossil Camponotini (see the “Notes”).

Finally, we point out that all future studies on fossils that may possibly be associated with Camponotus or Camponotini should critically evaluate the morphological evidence for placement in any of the extant genera particularly in reference to Ward et al. (2016) for workers and Ward and Boudinot (2021) for workers and alates (the wing venation characters apply equally to males and queens). A recent work which ignored these studies is Takahashi and Aiba (2023), which misidentified multiple specimens as Camponotus. If a species name must be given to a fossil that cannot be placed in any of the extant genera of Camponotini based on synapomorphies, we strongly encourage authors to place these fossils in the form genus †Camponotites so that uncertainty is explicitly recognized and to prevent the propagation of errors in macroevolutionary analysis.

I. Transferred to Liometopum (Dolichoderinae):

Compression fossil:

A. Shanwang formation [China, Linqu County; Miocene (Burdigalian), 20.4–16.0 Mya].

a. Liometopum Mayr, 1861.

= †Shanwangella Zhang, 1989. Syn. nov.

(1.) †L. palaeopterum (Zhang, 1989). Comb. nov. [q]. [Note 1].

= †S. palaeoptera Zhang, 1989.

• Combination in Camponotus: Hong and Wu 2000: 19.

II. Genus Camponotus Mayr, 1861, subgenus indet. [Note 2].

Copal fossil: Identifiable to species:

B. East African copal [Holocene, < 36 Kya (Solórzano-Kraemer et al. 2020)].

1. Ca. sp. THIS STUDY. [w]. [Note 3].

III. Genus Polyrhachis Smith, F., 1857.

Compression fossil:

C. Varvara formation [Miocene, 7.2–5.3 Mya].

1. †Po. annosus Wappler et al., 2009. [Note 4].

IV. Genus †Chimaeromyrma Dlussky, 1988, incertae sedis in tribe.

Amber fossil:

D. Sakhalin amber [Eocene, 47.8–41.3 Mya].

1. †Ch. brachycephala Dlussky, 1988. [Note 5].

V. Genus †Eocamponotus Boudinot, gen. nov. [Note 6].

Type species: †Eo. mengei (Mayr, 1868) by original designation.

Amber fossils: Identifiable to species:

E. Baltic ambers [Eocene, 37.8–33.9 Mya].

1. †Eo. mengei (Mayr, 1868). [w]. Comb. nov. [Note 7].

= †Eo. igneus (Mayr, 1868). Comb nov.

• Synonymized by Wheeler (1915): 138.

VI. Genus †Palaeosminthurus Pierce & Gibron, 1962 stat. rev., incertae sedis in Formicinae, unidentifiable hence invalid stat. nov.:

Phosphatized fossil:

F. Barstow formation, Calico member [USA, California; Miocene (Hemingfordian), 20.4–16.0 Mya].

(–.) †Pa. juliae Pierce & Gibron, 1962. [m]. Comb. rev.; unidentifiable, hence invalid, stat. nov. [Note 8].

= Formerly unresolved junior homonym of Camponotus juliae Emery, 1903.

• Transferred to Formicidae: Najt, 1987: 152.

• Status as species: Bolton, 1995b: 311.

• Transferred to Camponotus: Snelling, R.R. pers. comm. to Bolton, B. 2004, in Bolton (2023).

VII. Genus †Pseudocamponotus Carpenter, 1930, incertae sedis in tribe, unidentifiable hence invalid stat. nov.

Compression fossil:

G. Elko formation [Eocene, 37.2–28.4 Mya].

(–.) †Ps. elkoanus Carpenter, 1930. [q]. Unidentifiable, hence invalid, stat. nov. [Note 5].

VIII. Genus †Camponotites Steinbach, 1967, incertae sedis in Formicinae. [Note 9].

Amber fossil: Unidentifiable at neontological genus level:

H. Fushun amber [China, Liaoning, Jijuntun formation; Eocene (Lutetian), 47.8–41.3 Mya].

(1.) †Ctt. tokunagai (Naora, 1933). [q?]. Comb. nov. [Note 10].

Compression fossils: Unidentifiable at neontological genus level: [Note 11].

I. Green River formation [USA, Colorado; Eocene, 50.3–46.2 Mya].

(2.) †Ctt. vetus (Scudder, 1877). [q?]. Comb. nov. [Note 12].

J. Bouldnor formation, Bembridge Marls member [Great Britain; Eocene (Priabonian), 38.0–33.9 Mya].

(3.) †Ctt. cockerelli (Donisthorpe, 1920). [m]. Comb. nov.

= †Leucotaphus cockerelli Donisthorpe, 1920.

• Combination in Camponotus: Dlussky and Perfilieva 2014: 417.

K. Florissant formation [USA, Colorado; Eocene, 37.9–33.9 Mya].

(4.) †Ctt. fuscipennis (Carpenter, 1930). [q]. Comb. nov.

(5.) †Ctt. microcephalus (Carpenter, 1930). [q]. [Note 13]. Comb. nov.

(6.) †Ctt. petrifactus (Carpenter, 1930). [w]. Comb. nov.

L. Brunstatt, horizon d2 [France; Early Oligocene, 33.9–28.4 Mya].

(7.) †Ctt. compactus (Förster, 1891). [q]. Comb. nov.

(8.) †Ctt. vehemens (Förster, 1891). [m]. Comb. nov.

• Théobald, 1937: 218 (w, q, m).

= Senior synonym of †Ca. miserabilis Förster, 1891: Théobald, 1937: 218.

M. Creek near Bechlejovice [Czechia; Oligocene (Rupelian), 33.9–28.1].

(9.) †Ctt. novotnyi (Samšińák, 1967). [q]. Comb. nov.

N. Rott formation [Germany, Orsberg; Oligocene: 28.4–23.0 Mya].

(10.) †Ctt. lignitus (Germar, 1837). [q]. Comb. nov.

= †Formica lignitum Germar, 1837.

• Combination in Camponotus: Mayr, 1867: 51.

O. Niveau du gypse d’Aix Formation [France; Oligocene (Chattian), 28.1–23.0 Mya].

(11.) †Ctt. longiventris (Théobald, 1937. [q, m]. Comb. nov.

(12.) †Ctt. theobaldi (Özdikmen, 2010). [m]. Comb. nov.

• Replacement name for †Ca. saussurei Théobald, 1937.

(13.) †Ctt. penninervis (Théobald, 1937). [m]. Comb. nov.

A. Shanwang formation (see above).

(14.) †Ctt. ambon (Zhang, 1989). [q?]. Comb. nov.

(15.) †Ctt. ampullosus (Zhang, 1989). [q?]. Comb. nov.

(16.) †Ctt. curviansatus (Zhang, 1989). [q]. Comb. nov.

(17.) †Ctt. gracilis (Zhang, 1989). [m?]. Comb. nov.

(18.) †Ctt. longus (Zhang, 1989). [q]. Comb. nov.

(19.) †Ctt. microthoracus (Zhang, 1989). [q]. Comb. nov.

(20.) †Ctt. plenus (Zhang, 1989). [q]. Comb. nov.

(21.) †Ctt. shanwangensis (Hong, 1984). [q]. Comb. nov.

(22.) †Ctt. pictus (Zhang et al., 1994) [q]. [Note 14]. Comb. nov. • Previously junior primary homonym of Ca. ligniperda pictus Forel, 1886.

(23.) †Ctt. xiejiaheensis (Hong, 1984). [m]. Comb. nov.

• TYPE SPECIES of †Rabidia Hong, 1984.

• Combination in Oecophylla: Zhang, 1989: 297.

• Combination in †Camponotites Dlussky et al., 2008: 616.

P. Radoboj [Croatia; Miocene (Sarmatian), 12.7–11.6 Mya].

(24.) †Ctt. heracleus (Heer, 1849). [m]. Comb. nov.

= †Formica heraclea Heer, 1849.

• Combination in Camponotus: Mayr, 1867: 52.

• Also described as new by Heer, 1850: 116.

(25.) †Ctt. induratus (Heer, 1849). [m]. Comb. nov.

= †Formica indurate Heer, 1849.

Dlussky and Putyatina 2014: 249 (m, q).

• Combination in Camponotus: Mayr, 1867: 52.

• Also described as new by Heer, 1850: 116.

(26.) †Ctt. oeningensis (Heer, 1849). [q]. Comb. nov.

= †Formica obesa oeningensis Heer, 1849.

• Combination in Camponotus and raised to species: Cockerell, 1915: 486.

Q. Joursac [France; Miocene, 11.6–7.2].

(27.) †Ctt. obesus (Piton, 1935). [q?]. [Note 15]. Comb. nov.

R. Montagne d’Andance Saint-Bauzile, Privas [France, Ardèche; Miocene (Turolian), 8.7–5.3 Mya].

(28.) †Ctt. crozei (Riou, 1999). [q]. Comb. nov.

S. Brunn-Vösendorf [Austria; Miocene (Messinian), 7.2–5.3 Mya]

(–.) †Ctt. ullrichi (Bachmayer, 1960). [wing]. Comb. nov.; unidentifiable, hence invalid, stat. nov. [Note 16].

T. Willerhausen clay pit [Germany; Pliocene (Piacenzian), 3.6–2.6 Mya].

(29.) †Ctt. silvestris Steinbach, 1967. [q].

• †Camponotites Steinbach, 1967 TYPE SPECIES.

• Redescribed: Dlussky et al. 2011: 452.

(30.) †Ctt. steinbachi Dlussky et al., 2011. [q].

Note 1. The species †Ca. palaeopterus (Zhang, 1989) was originally attributed to its own genus, †Shanwangella Zhang, 1989 before being placed in Camponotus by Hong and Wu (2000). The fossil cannot be attributed to Formicinae at all, however, due to the presence of cross vein 2rs-m, which never occurs in Formicinae; this crossvein encloses the second submarginal cell of the wing. Because the specimen has 2rs-m, lacks postpetiolation of abdominal segment III, and does not have cinctation of abdominal segment IV (= presence of transverse sulci), we transfer the species to Dolichoderinae. Therein, the specimen is recognizable as an alate of Liometopum given its large size (discal and submarginal cells ~ 1 mm long), its massive gaster, and details of the venation. †Liometopum palaeopterum comb. nov. was discovered in Shanwang in the Shandong Province, reasonably within the current distribution of the extant species L. sinense Wheeler, 1921 (Del Toro et al. 2009). Moreover, it is plausible that the fossil represents an ancestral population given that L. sinense is the only species currently known from China, at least to present knowledge. Unfortunately, gynes and males are unknown for the extant species. The unusual head and antennae of †L. palaeopterum comb. nov. are here interpreted as preservational artefacts.

Note 2. Camponotus and the tribe Camponotini more broadly is one of the most challenging taxonomic puzzles in the Formicidae, and not merely due to the massive size of these taxa (1084 valid species and 411 valid subspecies are currently attributed to Camponotus at the date of writing, Bolton 2023). Although some genera in the tribe are reasonably identifiable based on external morphology (e.g., Ward et al. 2016), others, such as the fundamental distinction between Colobopsis—which is sister to all other Camponotini—and the hyperdiverse Camponotus is challenging even with extant material in hand and under the microscope (Ward and Boudinot 2021). For these reasons, we substantially revise the fossil system of Camponotus in order to meet the twin aims of: (1) cleaning up the useless species names attributed to Camponotus, and (2) discouraging uncritical use of these fossils for macroevolutionary analysis (e.g., Klimeš et al. 2022). Toward these aims, we have: (a) provided a new genus name for †Camponotus mengei, †Eocamponotus gen. nov., as this fossil cannot be confidently placed in Camponotus yet; (b) transfer red 29 fossil taxa from Camponotus to the form genus †Camponotites, which we treat as incertae sedis in Formicinae; and (c) transfer red one species out of the Formicinae altogether.

Note 3. The minor worker specimen (PMJ Pa 5829) is difficult to identify, given the limited resources available. We attempted to identify the specimen using Emery’s (1925) key to Old World Camponotus subgenera, Brian Taylor’s Ants of Africa website (Taylor 2022), and AntWeb (2022). Ultimately, we were unable to obtain a satisfying identification. In mesosomal form and postcephalic setation, the specimen resembles Camponotus (Myrmacraphe) furvus Santschi, 1911 but it differs in head shape and by having shorter palps. In Taylor’s key, the specimen runs to C. acvapimensis Mayr, 1862, yet it differs in mesosomal form. We therefore conservatively consider the specimen unidentified.

Note 4.Polyrhachis annosa neatly meets the expectations for Polyrhachis as it clearly has lateral petiolar spines, which is synapomorphic condition of the genus. Based on the limited preservation, we do not have confidence that this species will be placeable either in the stem or crown of the genus based on morphology. However, given that the Varvara formation is young, being dated at between 7–5 Myo, we do not think that it is defensible to place this fossil in a separate genus. We therefore leave this species in Polyrhachis with the hope that future phylogenetic work will resolve the polarity of petiolar spines within the genus.

Note 5. The monotypic genera †Chimaeromyrma and †Pseudocamponotus have been treated as incertae sedis in Camponotini, for which we see no specific morphological evidence to question these otherwise harmless placements. We choose to retain †Chimaeromyrma brachycephala Dlussky, 1988 as a valid genus and species as it is possible that the identification of this amber fossil may be refined through the application of µ-CT at some point in the future. As for †Pseudocamponotus elkoanus Carpenter, 1930, we doubt that this fossil will ever be identifiable given the lack of wing venation and very limited preservation of the single known specimen. Given that there is insufficient preservation to confidently place the species to tribe, we consider †Ps. elkoanus to be unidentifiable, hence invalid stat. nov. We do not synonymize †Pseudocamponotus with †Camponotites, however, as the former would take priority and we prefer the latter name as the form genus, given that it has the proper suffix (-tites) to indicate paleontological uncertainty.

Note 6. We erect the genus †Eocamponotus gen. nov. for †Camponotus mengei and its junior synonym †Ca. igneus as, although these fossils are sufficiently preserved for species diagnosis, formal combined-evidence analysis failed to support a relationship with any particular genus of the Camponotini (Boudinot et al. 2022a). In so doing, we aim to preclude the usage of this fossil in macroevolutionary analysis as a calibration point for the genus Camponotus. At most, this fossil species can be used as a calibration for the Camponotini; whether as a stem or crown calibration point, however, is much less certain, and a conservative approach would be for the stem of the tribe.

Note 7. We briefly note that †Ca. mengei was described alongside †Ca. igneus by Mayr (1868), and that the latter was accepted in a number of articles until Wheeler (1915) concluded that the latter is a subjective synonym of the former based on an examination of 103 Camponotus specimens and Mayr’s types of †Ca. mengei. Wheeler reported that the type specimens of †Ca. igneus were in the collection of Franz Anton Menge, which is presumably in Gdańsk, Poland. The valid species was originally considered to be a Ca. (Tanaemyrmex) but was recently suggested by Radchenko and Perkovsky (2021) to be Ca. (Camponotus) due particularly to the form of its clypeus, and the shapes of the head and mesosoma, without further specification. Reevaluation of the morphological affinities of this species is necessary.

Note 8.Ctt. juliae (Pierce & Gibron, 1962) comb. nov. is represented by a single male that was phosphatized in a calcareous nodule in the Calico member of the Miocene-aged Barstow formation in the Mojave Desert of California. The taxonomic history of this fossil is unusual. In its original description in Pierce and Gibron (1962), the fossil was classified as a new species of a new genus representing a new family of symphypleonan Collembola: †Palaeosminthurus juliae (†Palaeosminthuridae). These names went unnoticed for more than two decades, until the collembolist Dr Judith Najt (see Deharveng et al. 2017) observed that the preserved head, scape, thorax, and leg remnants of the fossil belong to a hymenopteran, which she identified as Camponotus (see Najt 1987). Subsequently, Roy R. Snelling examined the fossil, presumably at the Los Angeles County Museum, and concluded that the taxon is a junior synonym of Camponotus festinatus (Buckley, 1866) (Snelling 2006), an identification that was communicated to Barry Bolton in 2004 but went unpublished by the time of Roy Snelling’s death in 2008. Bolton provisionally accepted this hypothesis in his taxonomic catalog (Bolton 2023). Here, after critical consideration of the available morphological evidence, we exclude the species from Camponotus, and revive the genus †Palaeosminthurus stat. rev., which we consider to be incertae sedis in Formicinae and unidentifiable hence invalid stat. nov. Specifically, we attempted to run the specimen through the male-based key to all Nearctic genera of Smith (1943) and that of Boudinot for all New World formicine genera (see section 3.7.H of Boudinot 2020); there is simply too little structural detail preserved to render a meaningful identification of this fossil. Unless a method like laminar µ-CT may be applied successfully, we anticipate that this fossil will remain unidentifiable at the genus and tribal levels among the Formicinae.

Note 9. Here, we recognize the form taxon †Camponotites to which we transfer 29 species. †Camponotites should be categorically precluded from usage as calibration points for macroevolutionary analysis of the Formicinae or Formicidae. A balance for retaining and actively using this form genus is that the fossils in this taxon may be useful for paleogeographic study, so invalidation of this name may result in loss of paleostratigraphic information. Future work involving direct re-examination of these fossils is necessary to determine some of the taxa now placed in †Camponotites may perhaps be placed with more confidence among the genera of Camponotini—such as †Ctt. novotnyi (Samšińák, 1967) comb. nov. as this fossil is quite well preserved and clearly displays the major synapomorphy of the Camponotini, namely that the antennal sockets are separated posteriorly from the posterior clypeal margin. For this example, however, the remainder of the specimen is too poorly preserved to allow the fossil to be meaningfully associated with any extant genus of the Camponotini.

Note 10. From the illustration provided in the original description, it is not possible to confidently identify the specimen as a member of Camponotus. We retain this species as incertae sedis in the genus to encourage future work on the fossil, if possible.

Note 11. All of these fossils could be considered unidentifiable to species, hence invalid, but are here treated as incertae sedis in Camponotus to highlight their existence. Critically, because of the lack of morphological information, it is possible that a number of these taxa belong to other genera of Camponotini (see Ward et al. 2016 and Ward and Boudinot 2021). Reexamination of the original material is necessary in all cases.

Note 12. While it may be tempting to use †C. vetus as a calibration for Camponotus or the Camponotini, it cannot be confidently attributed to any living genus, subgenus, or species group due to insufficient morphological information.

Note 13. The generic placement of †Ca. microcephalus is dubious and should be confirmed through direct examination of type and additional material.

Note 14. Although †Camponotus pictus Zhang et al., 1994 is a junior primary homonym of Ca. ligniperda pictus Forel, 1886, we transfer this species to the form taxon †Camponotites, rendering a nomen novum unnecessary.

Note 15. The compression-fossil taxon †Ca. obesus is represented by fragments of the mesosoma, legs, and metasoma, all of which are preserved in a dorso-anterolateral oblique view. These remains are suggestive of Camponotus but otherwise cannot be identified meaningfully. Identification, in this case, is primarily driven by the rough similarity and absence of other ~14 mm long ants with an apparently rounded mesosoma in modern Western Europe.

Note 16. Bachmayer (1960) described †Ctt. ullrichi based on a single forewing from a Miocene-aged deposit in Austria. This ~10.3 mm long wing cannot be attributed to Camponotus or the Camponotini because free M diverges from Rs+M proxi‹mad 2r-rs by more than twice the length of that cross vein. In Camponotini, free M diverges at or distad 2r-rs (see Char. 499 on p. 293 of Boudinot et al. 2022b; also, Ward and Boudinot 2021). Because only Myrmelachistini in Formicinae have the split of Rs+M well proximad 2r-rs, and as these ants are miniscule, we would prefer to consider the taxon incertae sedis in Formicidae. However, as this would necessitate the recognition of another “trashbin’’ form taxon, we elect to place the fossil in †Camponotites and to consider it unidentifiable, hence subjectively invalid stat. nov.

Eocamponotus Boudinot, gen. nov.

Type species

Eo. mengei (Mayr, 1868) by original designation.


Incertae sedis in Camponotini. Subfamily Myrmicinae Lepeletier de Saint-Fargeau, 1835 Genus Crematogaster Lund, 1831

I. Species retained in Crematogaster.

Copal fossil: Identifiable to species:

A. African copal [Holocene, < 36 Kya (Solórzano-Kraemer et al. 2020)].

1. Cre. sp. THIS STUDY. [w].

II. Fossils excluded from Crematogaster:

Genus †Incertogaster Boudinot, gen. nov., incertae sedis in Myrmicinae. [Note 1].

Type species: †Inc. primitiva (Radchenko & Dlussky, 2019), by original designation.

B. Kishenehn formation [USA, Montana; 47.8–41.3 Mya].

(1.) †In. aurora (LaPolla & Greenwalt, 2015). [q]. [Note 2]. Comb. nov.

C. Rovno amber [Ukraine; Eocene, 38.0–33.9 Mya].

(2.) †In. praecursor (Emery, 1891). [m]. [Note 3]. Comb. nov.

D. Sicilian amber [Italy; Oligocene, 11.6–5.3 Mya].

(3.) †In. primitiva (Radchenko & Dlussky, 2019). [m]. [Note 3]. Comb. nov.

Note 1. We erect the explicit catchall taxon †Incertogaster gen. nov., into which we place †In. aurora comb. nov., †In. praecursor comb. nov., and †In. primitiva comb. nov. We do so in order to recognize that these latter two species are not meaningfully placeable in Crematogaster based on their preserved morphologies, and that †In. aurora requires renewed attention. We choose †In. primitiva as the type species as the specimen of †In. praecursor examined by Emery is likely lost (see, e.g., Boudinot et al. 2016), and as the compression fossils require revised scrutiny and may be placeable in other genera, whether extant or extinct.

Note 2.Crematogaster aurora is the oldest fossil attributed to the genus and is the most difficult to critique due to its highly suggestive but incomplete preservation. While we are uncertain about the placement of the fossil in Crematogaster due to the apparently axial postpetiolar helcium (i.e., located at about mid-height of AIV rather than atop AIV) and the unknown antennomere count, the specimen does indeed lack a vertically oriented petiolar node, at least as preserved. To prevent the use of this fossil for divergence dating analysis while the preserved anatomy is reevaluated, we transfer the species forming †In. aurora comb. nov. We hope that additional specimens may be found, or the known specimens are subjected to documentation using advanced techniques. One of the authors (BEB) examined both the type and the paratype of †In. aurora at the USNM and observed that the paratype differed substantially, having (possibly) antennal scrobes but more importantly a lateromedially narrow postpetiole that was anteriorly attached to abdominal segment IV (metasomal III). Additionally, this specimen possibly had a 2–3-merous antennal club. Altogether, this raises doubt about the attribution of the paratype to †In. aurora, which remains of uncertain identification at present.

Note 3. The amber-preserved males described by Emery as †In. praecursor comb. nov. and Radchenko & Dlussky as †In. primitiva comb. nov. are unlikely to be representatives of either the stem or crown of the genus Crematogaster and are incertae sedis in the Myrmicinae within †Incertogaster. Both specimens have 13-merous antennae, while all Crematogaster males examined by the lead author have antennae that are 10–12-merous (Bolton 2003, p. 286; BEB, unpubl. data). Other diagnostic features include the short scape, which is ≤ 2 × the length of the pedicel, the pedicel shape, which is globular rather than cylindrical, and the mandibles, which are reduced or otherwise vestigial; the anterodorsal position of the postpetiolar helcium on abdominal segment IV can be difficult to discern. Unfortunately, Emery did not illustrate the wings or the face of †Cr. praecursor, so the fossil may need to be considered unidentifiable, hence subjectively invalid, if the specimen does not resurface. †Crematogaster primitiva, on the other hand, is well illustrated; its scapes are about 4 × the length of the pedicels, and the pedicels are not swollen or globular in shape. The mesosoma of this fossil (PMJ Pa 5824) is large and the mesoscutum is impressed, as in many Crematogaster, but the long and strongly nodiform petiole also contradict placement in that genus. At present, we cannot confidently attribute †Cr. primitiva to any valid generic taxon.

Incertogaster Boudinot, gen. nov.

Type species

Inc. primitiva (Radchenko & Dlussky, 2019), by original designation.


Incertae sedis in Myrmicinae. Genus Pheidole Westwood, 1839

Amber/copal species: Identifiable to species:

A. Mexican amber [Miocene, 23.0–16.0 Mya].

1. †Ph. pauchil Varela-Hernández & Riquelme, 2021. [w].

B. Dominican amber [Miocene, 20.4–13.8 Mya].

2. †Ph. anticua Casadei-Ferreira et al., 2019. [w].

3. †Ph. primigenia Baroni Urbani, 1995. [w].

4. †Ph. tethepa Wilson, 1985. [w]. [see Wilson 1985a].

C. East African copal sensu lato [Holocene, < 36 Kya (Solórzano-Kraemer et al. 2020)].

5. ‡Ph. rasnitsyni Dubovikoff, 2011. [w]. [Note 1].

D. East African copal or Defaunation resin [Holocene, < 36 Kya (Solórzano-Kraemer et al. 2020)].

6. ‡Ph. cordata (Holl, 1829). [w, s]. [Note 2].

= †Formica cordata Holl, 1829.

• Neotype here designated (specimen Pa 5889).

Compression fossil species: Species inquirenda.

E. Florissant formation [USA, Colorado; Eocene, 37.9–33.9 Mya].

(1.) †Ph. tertiaria Carpenter, 1930. [q]. [Note 3].

Note 1. Similar to the recent description of a Dorylus from putative Baltic amber (see section 4.2.1), the species ‡Ph. rasnitsyni was initially interpreted as an Eocene fossil (Dubovikoff 2011) but later reidentified as copal based on reevaluation of the material (Dubovikoff pers. comm. in Perkovsky 2016).

Note 2. We designate one soldier (= major) from the PMJ Pa collection (PMJ Pa 5889, copal, 14C-dated: ~700 years old) as the neotype of the ‡Ph. cordata, and tentatively associate a minor worker (PMJ Pa 5827) with this name although we do not recognize this as a secondary type. See section for elaboration and Casadei-Ferreira et al. (2019) for a recent review of this taxon.

Note 3. Given the single photograph available for this species, which is otherwise reported from two specimens (Carpenter 1930), we consider †Ph. tertiaria in need of revised study, and strongly recommend against its use in divergence dating analysis until definitive synapomorphies of Pheidole may be documented. Most notably would be the occurrence of cross vein 2rs-m, which encloses the second submarginal cell and is otherwise absent from other Myrmicinae with the exception of various Myrmicini and Pogonomyrmecini. Pheidole taxon treatment

Pheidole cordata (Holl, 1829)

Figs 19, 20, 21, Appendix 1: Fig. A5


PMJ Pa 5889, designated here. Figs 19A–D, 20A–D, 21B, D, F.

Figure 19. 

A–D. 3D-reconstruction of the neotype of ‡Pheidole cordata A. Habitus in lateral view; B. Habitus in frontal view; C. Habitus in dorsal view; D. Habitus in ventral view. Abbreviation: ppd = propodeum.

Figure 20. 

A–D. 3D-reconstruction of the neotype of ‡Pheidole cordata preserved in piece PMJ Pa 5889. A. Details of head in frontal view, arrow indicates occipital lobe; B. Detail of mouthparts in ventral view; C. Details of foreleg in lateral view; D. Details of metasoma in dorsolateral view. Abbreviations: IHT = inner hypostomal tooth, OHT = outer hypostomal tooth.

Figure 21. 

A, C, E. Copper lithographs by Schweigger (1819), which Holl (1829) named †Formica cordata. B, D, F. Photographs of the neotype of ‡Pheidole cordata A. Overview of the amber piece; B. Overview of the amber piece, arrow indicates the inclusion; C. Habitus in lateral view; D. Habitus in ventrolateral view; E. Habitus in dorsal view; F. Habitus in dorsolateral view.

Locality and horizon

East African copal (IAA results for PMJ Pa 5889: copal (Table 1); 14C-dating for PMJ Pa 5889: ~700 years old).


Platygastridae, Ceratopogonidae, and Lepidoptera.


The cuticle is preserved as a distinct layer as seen in the SR-µ-CT scan data. Most of the soft tissues are absent, except for parts of the digestive tract and some musculature, such as parts of the mandibular adductor (0 md1) and some muscles of the legs. The endoskeleton of the head and mesosoma is distinctly preserved and can be meaningfully used for future comparative anatomy.




The species, represented by the major worker, is identifiable as a member of the Ph. megacephala species group by (1) the presence of the conspicuous ventral convexity of the postpetiolar sternum (Fig. 19A; e.g., Salata and Fisher 2020). It differs from Ph. megacephala (Fabricius, 1793), Ph. megatron Fischer & Fischer, 2013, and Ph. spinosa Forel, 1891 by (2) the well-developed inner hypostomal teeth (Fig. 20B; e.g., Salata and Fisher 2022). Among the megacephala group species more broadly (e.g., Fischer et al. 2012), it differs in having (3) facial rugosity that extends to the posterior margin of the occipital lobes (Fig. 20A, note: among type specimens of the group imaged on AntWeb, this condition also occurring in Ph. megacephala impressifrons Wasmann, 1905, which has a more angular bulge of the postpetiolar sternum). See the description below for further conditions.


Measurements (in mm; abbreviations follow Salata and Fisher 2022): EL = 0.152; HL = 1.290; HW = 1.230; MTL = 0.673; PNW = 0.618; PPW = 0.324; PSL = 0.202; PTW = 0.172; SL = 0.714; WL = 1.110.

Indices (also following Salata and Fisher 2022): CI = 95.3; MTI = 54.7; SI = 58.0; PNI = 50.2; PPI = 26.3; PSLI = 16.4. Note: Measurements taken from cross-sectional projections in DragonFly using the reregistration and ruler tools.

Head. In full-face view (Figs 19B, 20A), the head is subcordate, with the lateral margins widest somewhat beyond head midlength and with the posterior portions of the lateral margins converging posterad to the occipital lobes. In lateral view (Fig. 19A), the head is subovate. The antennal scrobes are indistinct. The occipital lobes are rugose, with shagreened interspaces. The inner hypostomal teeth are well-developed; they are distant from the outer teeth, which are also well-developed (Fig. 20B). The median hypostomal tooth is indistinct.

Mesosoma. The humeral tubercle of the pronotum is weakly developed. The mesonotal bulge is distinct but not pronounced. The metanotum is only weakly indicated by a slight angularity of the promesonotal profile in lateral view. The propodeal spines are moderately long, with a wide base and acute tip (Fig. 19A).

Metasoma. The bulge of the postpetiolar sternum is rounded anteriorly. The first gastral tergum (ATIV) appears to be shagreened at its base (Fig. 20D).

Setation. Length and stature of setation uncertain, although density measurable in the scans based on the distinct occurrence of the setiferous punctation.

Coloration. Not clearly visible; appears brownish/reddish.

Remarks on the neotype

Designation of the soldier in piece PMJ Pa 5889 as the neotype of ‡Ph. cordata meets the requirements of article 75 of the ICZN (1999), as follows. 75.3.1. The identity of this taxon is in severe need of clarification, as it has vexed systematists for nearly two centuries (e.g., Mayr 1868; Casadei-Ferreira et al. 2019) and may mistakenly be used for evolutionary inference, such as an Eocene-aged calibration for divergence dating based on the assumption that it is from Baltic amber, as recorded by, e.g., Bolton (1995, p. 319) and Bolton (2003). 75.3.2, –.3. Diagnostic remarks and description are provided above. 75.3.4. The original material is known to be lost (Casadei-Ferreira et al. 2019). It is unclear if the material sent by Schweigger ever made it to the MfN Berlin in the first half of the 19th century; see p. 111 of Schweigger (1819) and elsewhere for his stated intent to have the specimens identified there. Further, Holl (1829, p. 140) indicates that he defined his species †Formica cordata based on the observations of Schweigger and Mayr (1868, p. 18) explicitly states that he had not seen the material referred to by Holl. 75.3.5. The neotype matches the best available evidence. More specifically, the first author of the present work directly examined a physical print of the original illustrations by Schweigger (1819, figs 70, 70a, 70b on plate 8 therein; Fig. 21A, C, E), which were used by Holl (1829) to designate the species. Based on this, that author observed clearly illustrated 3-merous antennal clubs, which would rule out other Afrotropical Myrmicinae (Fisher and Bolton 2016). The illustrations further show attributes of Pheidole, including a massive head, high and domed promesonotum, low and spined propodeum, and long petiolar peduncle with a short node. Mayr (1868) was uncertain about the size of the original material, which is unknowable at this point and irrelevant for the present designation. Therefore, we interpret the fossil as Pheidole based on the available evidence (Fig. 21B, D, F), which is restricted to the examined copper plate due to loss of the original material. 75.3.6. The designated neotype does come from the original type locality and horizon as much as is practicable, given that Schweigger (1819): (a) knew about copal (pp. 103, 104 therein) and East African copal was available around that time (e.g., Smith 1868, see section 4.3.2 below); (b) he was uncertain about the provenance of the two specimens eventually named ‡Ph. cordata by Holl (1829), as stated in the text; and (c) he pointed out that the species he examined resembled a taxon possibly from Africa (“Diese Bildung findet sich an Ameisen südlicher Länder.”, pp. 119 therein). Regarding the type locality further, although we cannot be absolutely certain that the specific fossil is from East African or Malagasy copal sensu lato, the syninclusion of a Pheidole minor from the PMJ Pa collection with Dorylus (PMJ Pa 5827), which has never been recorded from Madagascar, strongly implies that the material was from the mainland of the African continent. 75.3.7. The neotype is permanently preserved in and available for study at the Phyletisches Museum, Jena.

We have taken this action to resolve a suite of problems associated with the name ‡Ph. cordata, as recently reviewed by Casadei-Ferreira et al. (2019), who, after much consideration, concluded by placing this fossil incertae sedis in Myrmicinae. We fully agree with Casadei-Ferreira et al. (2019) that this fossil needs to be disposed of in order to avoid its uncritical use in systematic or evolutionary study and inference. By placing the name ‡Ph. cordata back in Pheidole, we alleviate the need for treating this taxon in the next revision of the fossil record of Myrmicinae, particularly as the specific epithet will be paired with the genus Pheidole, unless it were returned to Formica, to which it certainly cannot belong. Further, by designating a neotype we permanently fix this name to a known specimen that is both preserved in perpetuity in the PMJ Pa collection and is available for global evaluation via the cybertype data. Finally, there is no possibility beyond egregious error for this taxon to be used as an Eocene calibration for Pheidole as the neotype is from 14C-dated copal. (copal sensu lato).

Remarks on Afrotropical Pheidole

It is widely appreciated among myrmecologists working on Pheidole that the genus is in severe need of revision both globally and in the Afrotropical region (Wilson 2003; Fischer et al. 2012; Sarnat et al. 2015), which is also the particular case for the megacephala species group (Fischer et al. 2012; Salata and Fisher 2022). While we would strongly prefer to not provide a one-off description of a Pheidole due to this complicated problem, we accept this as necessary and acceptable only in order to resolve the problem of ‡Ph. cordata, which is otherwise an irksome thorn-in-the-side bestowed upon generations of us by the well-meaning cataloging work of Holl (1829).

Although ‡Ph. cordata as typified here cannot be included in barcoding or phylogenomic datasets given its poor soft tissue preservation, it is our hope that the SR-µ-CT data may allow the confident and quantitative placement of this species among the species allied to Ph. megacephala via a dedicated revision of this species group. As noted in our diagnosis above, the neotype of ‡Ph. cordata (PMJ Pa 5889) is most similar to Ph. megacephala impressifrons, being most starkly distinguished from this form by the form of the postpetiolar sternum in lateral view. Notably, the form of the medial hypostomal teeth has not been recorded for the various forms of Ph. megacephala and similar species (e.g., Fischer et al. 2012). Whether the newly typified species ‡Ph. cordata is extant is an open question; it is plausible that the historical habitat has been destroyed, hence this species may be considered a candidate Lazarus taxon. Further exploration of known Afrotropical copal sensu lato and extant myrmecofauna will be of considerable value.

3.3.3. Order Neuroptera: Synopsis of Nevrorthidae Family Nevrorthidae Nakahara, 1915. [Note 1]

I. Genus †Balticoneurorthus Wichard, 2016.

A. Baltic ambers [Eocene, 37.8–33.9 Mya].

1. †Ba. elegans Wichard, 2016. [m].

II. Genus †Cretarhopalis Wichard, 2017.

B. Kachin amber [Myanmar; Cretaceous, 99.6–93.5 Mya].

1. †Crh. patrickmuelleri Wichard, 2017. [f].

III. Genus †Electroneurorthrus Wichard, Buder & Caruso, 2010.

A. Baltic ambers [see above].

1. †El. malickyi Wichard, Buder & Caruso, 2010. [f].

IV. Genus †Girafficervix Du, Niu & Bao, 2023.

C. Daohugou shale [China; Jurassic, 166.1–157.3 Mya].

1. †G. baii (Du, Niu & Bao, 2023). [l].

V. Genus †Palaeoneurorthus Wichard, 2009.

A. Baltic ambers [see above].

1. †Pa. bifurcatus Wichard, 2009. [m].

2. †Pa. eocaenus Wichard, 2016. [m].

3. †Pa. groehni Wichard, Buder & Caruso, 2010. [m].

4. †Pa. hoffeinsorum Wichard, 2009. [m]. [Type species!].

VI. Genus †Proberotha Krüger, 1923.

A. Baltic ambers [see above].

1. †Pr. dichotoma Wichard, 2016. [f].

2. †Pr. eocaenus Krüger, 1923. [m, f]. [Type species!].

VII. Genus †Rhopalis Pictet, 1854.

A. Baltic ambers [see above].

1. †Rh. relicta Pictet, 1854. [f, m]. (See also: Wichard et al. 2010.)

VIII. Genus †Sisyroneurorthus Nakamine, Yamamoto, Takahashi & Liu, 2023.

B. Kachin amber [see above].

1. †S. aspoeckorum Nakamine et al., 2023. [f].

Note 1. Six of the eight fossil genera of Nevrorthidae are monotypic. For those two genera that have more than one species attributed to them, the type species is indicated. Genus Palaeoneurorthus Wichard, 2009

Palaeoneurorthus Wichard, 2009

Type species

Palaeoneurorthus hoffeinsorum Wichard, 2009.


This genus can be characterized by the forewing with costal cross veins almost all simple, the cross veins 3rp3+4-rp2 present in forewings and absent in hindwings, the flattened male sternum 9 with tongue-like tip and the needle-like male gonapophyses 9.


One male specimen in the amber collection (PMJ Pa 5874) is a member of Nevrorthidae. It was assigned to the genus Palaeoneurorthus based on our examination (Fig. 22A). We briefly characterize this specimen below:

Figure 22. 

Palaeoneurorthus sp. (Nevrorthidae) preserved in piece PMJ Pa 5874. A. Overview; B. Wing venation; C. Wing venation drawing; D. Genitalia; E. Genitalia drawing. Abbreviations: e = ectoproct, gp9 = gonapophyses 9, gst9 = gonostyli 9, gx9 = gonocoxites 9, T9 = tergum 9.

Palaeoneurorthus sp.


Body length ca. 3.0 to 4.0 mm; forewing length 7.5–7.8 mm, hindwing length 6.4–6.8 mm.

Head. Ocelli absent. Antenna slenderly filiform, with slightly enlarged scapus, smaller pedicellus, and 30 flagellomeres. Maxillary palps and labial palps not visible.

Wings (Fig. 22B, C). Elliptical, translucent. Forewing venation with trichosors present among marginal forks of RA, RP, MA, MP, CuA and CuP; all costal cross veins simple. Sc and RA almost parallel to margin, connected basally and subdistally by two and one cross veins, respectively. RP with three main branches. MA fused with RP at proximal 1/3 of wing, distally branched. MP proximally separated into two main branches, with each branch bifurcated distad. Cu branching near wing base; CuA with seven pectinate branches; CuP sinuate, simple, forked distad. A simple. Most cross veins present at base, middle and distal 1/3. Hindwing venation: Basal part of the hindwing not visible. Trichosors present among marginal forks of RA, RP, MA, MP, CuA and CuP; costal cross veins on proximal 2/3 not visible, distal 1/3 simple. Sc and RA almost parallel to margin, subcostal cross veins absent. RP with two main branches. MA fused with RP at wing proximal 1/3, distally forked. MP with two main branches, one branch bifurcated distally and the other proximally, respectively. Cu branching near wing base; CuA with ten pectinate branches, CuP straight, simple. A not visible. Only two rows of cross veins visible, present at middle and distal 1/3, respectively. In forewings the cross vein 3rp3+4-rp2 present; in hindwings cross vein rp3+4-rp2 absent.

Abdomen (Fig. 22D, E). Visible part of abdominal segment 9 annular. Sternum 9 not visible. Robust gonocoxites 9 (= “gonocoxa” in Boudinot 2018) strongly incurved, with broad base, apically tapering, with strongly sclerotized, claw-like gonostyli 9 (= “stylus” in Boudinot, 2018), which are directed ventromedially. Ventrolateral lobes (= gonapophyses 9, “penital sclerites” in Boudinot 2018) consist of two needle-shaped projections, which are distinctly spaced; dorsal projection slightly longer than ventral one, both pointed apically. Ectoproct (= “proctiger” in Boudinot 2018) broad, slightly convex at middle and distinctly protruding on both sides in dorsal view.


There are four described species belonging to Palaeoneurorthus, which are all known from Baltic ambers (Wichard 2009, 2016, Wichard et al. 2010). Among the four species of Palaeoneurorthus with males described our collection shares similarities with P. eocaenus in having the set of two needle-like projections of gonapophyses 9, and the ventral projection of gonapophyses 9 being shorter than the dorsal one longer. However, based on our examination, the ventral projection of gonapophyses 9 is slightly shorter than the dorsal one (Fig. 22C), whereas the dorsal projection is almost five times longer in P. eocaenus (Wichard 2016: fig. 6f). That the sternum 8 and the base of gonapophyses 9 are not visible impedes a further comparison. Thus, we currently treat this amber as Palaeoneurorthus sp.

3.3.4. Order Coleoptera Synopsis of fossil Doliopygus (Platypodinae) Genus Doliopygus Schedl, 1939

Copal taxa:

A. East African “copal” [Holocene, 0.0–0.0 Mya].

1. D. crinitus Chapuis, 1865. [Note 1].

2. D. tenuis Strohmeyer, 1912. [Note 1].

B. Defaunation resin or copal (possible East African) [Holocene, 0.0–0.0 Mya].

3. D. cf. serratus HERE. [Note 2].

Note 1. Doliopygus crinitus and D. tenuis were identified by Schedl (1939) from East African copal as species of Crossotarsus, with this original material presumably associated with the material misidentified as Baltic amber by F. Smith (e.g., Smith 1868; Grimaldi et al. 1994; O’Hara et al. 2013; see Note 2 of Dorylus above).

Note 2. We do not have the expertise to confidently identify the µ-CT scanned specimen to species level, thus we appreciate the identification suggested by Bjarte Jordal. Doliopygus is known to be paraphyletic (Jordal 2015), with D. serratus being close to D. chapuisi (B. Jordal, pers. comm. 9 Nov 2022). Given the objective of the present manuscript, the tentative species identification is sufficient to resolve our uncertainty about the age of the resin matrix. Family Mordellidae Latreille, 1802

Mordellidae Latreille, 1802


We do not provide a taxonomic synopsis of Mordellidae here as the fossil record of the family has been recently treated by Batelka et al. (2023). †Baltistena (a collective group name established by Batelka et al. 2023)

Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov.


The species name nigrispinata refers to distinctly black combs on metatibia and tarsomeres contrasting with orange surface of the cuticle.

Type materials

Holotype. PMJ Pa 5870, Baltic amber. Sex indeterminable. Cybertype: Appendix 1: Fig. A6.

Paratypes. None.

Differential diagnosis

The species belong to the subgroup of Mordellistenini with emarginated or dilated penultimate pro- and mesotarsomere sensu (Ermisch 1950). To this possible clade belong twelve of fourteen of Baltic Mordellistenini so far described (Batelka et al. 2023). In †B. nigrispinata sp. nov. the eyes are glabrous without interfacetal (= interommatidial) setae as in †Palaeostena eocenica Kubisz from which it differs by lower number of combs on metatibia and metatarsomeres I and II, and by the shape of palpomere IV which is type C1 sensu Franciscolo (1957) in †Palaeostena. The ultimate maxillary palpomere is securiform as in †Baltistena korschefskyi (Ermisch) from which †B. nigrispinata sp. nov. differs by the absence of combs on metatarsomere III and by the comb formula. The ring of short black scale-like setae on the tip of pygidium is similar to that in †Baltistena brevispina Batelka, Rosová & Prokop and in †Palaeostena eocenica. The metakatepisternum is fused early with the metaventrite in the middle of its posterior edge, which has so far only been observed in †Palaeostena eocenica among the Eocene Mordellistenini, while the other four species described by Batelka et al. (2023) have a separate and discernible metakatepisternum that is elongate and extends to the metanepisternum. Based on the shape of the body, the glabrous eyes, the shape of the metakatepisternum, and the setae on the cauda, †B. nigrispinata sp. nov. most closely resembles †Palaeostena eocenica. Also, while adding the species into the key provided by Batelka et al. (2023) it is coupled with †Palaeostena eocenica and †Baltistena amplicollis (Ermisch). From the last species, †B. nigrispinata sp. nov. differs by the comb formula, the shape of the ultimate maxillary palpomere, and the length of antennomeres III and IV, combined compared to antennomere V.

This set of characters observed for †B. nigrispinata sp. nov. supports the hypothesis that the species of Baltic Eocene Mordellidae formed a characteristic fauna that was much different from extant European representatives (Batelka et al. 2023).


Head subglobular, frons continuously convex, hind margin of eye at posterior margin of head, elytra convex, pygidium long, metacoxa broad, comb formula 3//2/1/0/0. Habitus in lateral view (Fig. 23A, Fig. 24A).

Figure 23. 

A–C. Holotype of †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (Mordellidae) preserved in piece PMJ Pa 5870. A. Habitus; B. Left antenna; C. Right metathoracic leg. Abbreviations: an3–an11 = antennomeres 3–11, ta1–4 = tarsomeres 1–4.

Figure 24. 

A–F. 3D reconstruction of the holotype of †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (Mordellidae). A. Habitus in lateral view; B. Antennomeres I–VI; C. Maxillary palpomeres; D. Habitus dorsally (scutellar shield pointed by arrow); E. Pronotal disc; F. Metatibial spurs; G. Thorax laterally. Abbreviations: an3–an6 = antennomeres 3–6, mtbs = metatibial spurs, mtcx = metacoxa, mtfe = metafemur, mte = metanepisternum, mtep = metepimeron, mttr = metatrochanter, mtke = metakatepisternum, mtve = metaventrite, mxp2–4 = maxillary palpomeres 2–4, ped = pedicel, prn = pronotum, sca = scape, ta1–4 = tarsomeres 1–4.

Main diagnostic characters as defined by Franciscolo (1967) and Batelka et al. (2023): Right antenna well visible, left antenna (Fig. 23B) visible from basal part of antennomere II, antennomeres subcylindrical, slightly compressed, without any lateral projections, antennomeres III–IV slightly widening towards apex (Fig. 24B), length ratios of antennomeres as follows: ?-1.4-1.0-1.25-1.6-1.4-?-?-?-1.6-2.0; antennomere XI regularly rounded at apex; antennae densely covered by erect or semierect sensilla from antennomere III. Maxillary palpomere I small, palpomere II prolonged, widest at apex, palpomere III short, triangular, palpomere IV long, securiform of Mordella-type (Franciscolo 1957: fig. 6_A1) (Fig. 24C). Eyes finely faceted; Eyes glabrous without interfacetal setae. Scutellar shield continuously rounded (Franciscolo 1957: fig. 9_type10) (Fig. 24D). Basal side of pronotal disc widely convex in central part (Fig. 24E). Elytra 3.2 × as long as pronotal disc. Form of protarsi indiscernible. Structure of protibia indiscernible. Mesotarsomeres I – III cylindrical, tarsomere I 6.1 × as long as wide; tarsomeres II and III 5.0 × as long as wide; tarsomere IV excised almost to middle region; tarsomere V about 3.0 × as long as wide. Mesotibia very slightly shorter than metatarsomeres combined. Metatibia (Fig. 23C) with three distinct lateral combs of scale-like setae including preapical comb, combs do not reach middle of metatibia; preapical comb runs parallel with apical fringe of setae, remaining two combs slightly oblique; few isolated patches of scale-like setae inserted posterior to last dorso-lateral comb. Metatibia with two spurs, outer spur shorter than inner one (Fig. 24F). Metatarsomeres (Fig. 23C) I–IV with row of spiniform setae consisting ventrally of 12 to 17 short, strong setae, formula: 17/14/12/15; metatarsomere I with two black and short lateral combs of scale-like setae and three isolated patches of black setae; metatarsomere II with one short lateral comb of scale-like setae and one black isolated seta, metatarsomeres III – IV without combs; length ratio of metatarsal segments 2.2-1.2-1-1. Pygidium long and straight, 2.4 × as long as hypopygium. Metanepisternum long and narrow, lower corner of posterior edge rounded, anterior edge 3 × as long as posterior edge, ventral edge 7.5 × as long as posterior edge (Fig. 24G). Metakatepisternum restricted to ventral part of thorax, fused with median portion of posterior edge of metaventrite (Fig. 24G). Pretarsal claws long and straight, with 2 indistinct teeth on ventral edge. Tip of pygidium with ring of short black scale-like setae. Lengths in mm: pronotal disc = 0.46, elytra = 1.29, mesotibia = 0.46, metatarsomere I = 0.38, pygidium = 0.73, body without head = ca. 2.

4. Discussion

4.1. Geological provenance of the rediscovered PMJ Pa amber collection

Between the taxonomic and color qualities of the resin pieces, coupled with the IAA results (Table 1), we were able to sort the fossils into Baltic amber and African copal categories to our satisfaction. Initially, the conflict among the qualitative tests and the results from the IAA confounded us. After considering these results, the true significance of the biotic inclusions, however, became clear, resolving the conundrum of fossil source. From our perspective, it was deeply surprising to find specimens interpreted as copal from the IAA tests that were directly labelled as from “Samland Kleinkuhren” in the PMJ Pa collection, especially as there are no reports, to our knowledge, that copal has been found in the Samland Peninsula (See also 4.2.2.). While we were initially skeptical that labels and objects might have been mixed in the small PMJ Pa collection, this seems to be the most likely scenario. We note that von Knorre kept the collection as it was given to him, thus the collection has not been seen and processed until now. The evidence from the PMJ Pa amber collection clearly shows a shift in source, especially from “without” to a confidently assigned one and simply false labeling could be resolved, and thus presents in a small scale what it might look like in another, larger collection.

At the bottom line, the scenario we encountered with this collection illustrates two critical points: (1) the importance of the correct labeling of any specimen, further underscoring the value of accurate corresponding information for contemporary and future research (King 1975; Corado 2005; Donovan and Riley 2013); and (2) the necessity of skepticism for fossils, even when having label data, as it was only the combination of biotic and chemical data that allowed us to draw confident conclusions about “amber” provenance in the present study. While the chemical or biotic evidence alone may have been sufficient, our uncertainty was not resolved until we had both lines of evidence, which clearly showed the inadequacy of the qualitative tests that have been supposed to differentiate between amber and copal.

4.2. Historical conspectus

To arrive at a more comprehensive understanding of the Phyletisches Museum amber collection and the materials contained therein, it was necessary to review the historical literature on amber in general (section 4.2.1) and on the Kleinkuhren locality in particular (section 4.2.2).

4.2.1. From the amber road to the 19th century

In antiquity, Tacitus (circa 56–120 AD) correctly concluded that amber was a tree resin: “sucum tamen arborum esse intellegas, quia terrena quaedam atque etiam volucria animalia plerumque interlucent, quae implicata humore mox durescente materia” (that it is a tree sap, however, can be seen from the fact that some crawling, but also flying animals are often visible between, which get into the liquid and are then trapped when the material hardens) Tac. Ger. 45.6 The Baltic Sea has been a source of amber well before the time of Tacitus, as amber from this region has been found in neolithic burial sites (Singer 2016). There exists much older evidence for the use of amber, such as in the cave of Isturitz, dating back to 34,000 years ago (King 2022), but only a brief outline with a focus on Baltic amber shall be given here as full-length books have been published on the subject from various perspectives (e.g., Brost and Dahlstrom 1996; Grimaldi 1996; King 2022).

Through the so called “Amber Road”, an ancient trade route, amber was exported from Europe to Asia, the Mediterranean Sea and Egypt (Singer 2008, 2016). Amber might have reached Egypt directly by sea or via Syria, of which the famous Quatna lion would be proof (Mukherjee et al. 2008). In the neolithic era the first use of amber was certainly due to superstition and so the transparent, flammable and, when rubbed, fragrant material was attributed with protective properties. It was worn by the living as jewels or donated as precious grave goods (Andrée 1951; Frondel 1968; Larsson 2010; Vijande Vila et al. 2015). The scientific use of inclusions played a subordinate role during antiquity, despite a few correct inferences that amber is a tree resin and is originally liquid, for example, Tacitus (see above), Aristotle (Meteorology 4.10), or Pliny the Elder (Plin. Nat. 37.11). Nevertheless, the “amber effect” was already known by Plato, which is the oldest mention of the fact that rubbed amber attracts lightweight objects placed near it (Assis 2010). With this only applying to amber, our present terms “electric” and “electricity” are derived from the Ancient Greek ἤλεκτρον (ēlektron) (Andrée 1951).

Considerable time passed until inclusions became demonstrably more important for science, from the Bronze Age via ancient scholars up to the 16th century. As early as in the beginning of 14th century, the paternoster makers used amber for their necklaces (Buchholz 1961; Hinrichs 2007). Amber as jewellery and art is still widely appreciated today (Pileckaitė 2001; Goldenberg 2004; Sado 2022) and one of the most famous goldsmiths in the last century was Toni Koy (1896–1990). Written evidence for the beginning of a scientific use was provided by scholars, such as medical doctors and pharmacists, or affluent persons interested in natural history.

One of the first scientific records, found in Gessner (1565)[-1566], is about the mineral collection of Johannes Kentmann (p. 22–24), who listed in his order “Succina gravida” few insects in amber, for example “5. Eiufdem coloris, in quo formica. Darin ein omeiß.”, i.e., an ant is within. In his work he used the system of minerals published by Agricola (1546) and was in fact one of the first scholars to put it into practice. A comparable scientific collection of that time was owned by Michele Mercati, an Italian polymath (cf. Hinrichs 2007), whose work was published posthumously in 1717 (Mercati 1717; King 2022). Amber was an attractive object in the so-called Wunderkammern (cabinets of curiosities), where it was valued more for its beauty than for scientific reasons. Probably one of the best-known wonder chambers is the famous “Grünes Gewölbe” in Dresden (Germany), while the most famous and mysterious is the Bernsteinzimmer of Königsberg, which was established by the Prussian king Frederick I in 1701 and the following years, and vanished in 1944, in the turmoil of war. The possible survival and whereabouts of this assembly of amber remain a mystery.

In 1742 Nathanael Sendel published his “Historia Succinorum” on the Dresdner amber collection of Augustus the Strong (Augustus II, “August der Starke”) and his son Friedrich August II. In this remarkable work, which largely deals with animals enclosed in amber as shown in part one “Historia insectorum succino conditorum” (Sendel 1742), he laid the foundation of modern amber research (Wichard and Wichard 2008). Even if Sendel erroneously assumed that amber was formed by soil in so-called “Gagat-Veins”, as well as some inaccurate species determinations (Greven and Wichard 2010), the merit of this work is undisputed, due in part to the 13 rich lithographs by Christian Friedrich Boetius (1706–1782). Another breakthrough in amber research was achieved by Georg Carl Berendt with his “Die Insekten im Bernstein”. Berendt was clearly ahead of his time, as he concluded “[…] die Art ist verschwunden. Dass sie ausgestorben sei, lässt sich nicht behaupten […] wahrscheinlich ist sie durch das veränderte Klima nur verdrängt […] ” ([…] the species disappeared. It cannot be said it is extinct […] it has probably only been displaced by the changing climate [...]) (Berendt 1830, pp. 37). The issue of climate change is today more relevant than ever (Flannery 2009, Tollefson 2022), and amber inclusions can provide valuable evidence (Słodkowska 2013; Penney 2010; Penney et al. 2013; Solórzano-Kraemer et al. 2020). Moreover, Berendt was aware of the importance of inclusions for the study of earth’s history, and he saw evidence against the constancy of species (Berendt 1830, pp. 5 and 6; Hinrichs 2007). With Berendt a modern state of amber research was reached, with a broad knowledge of insects, and cooperation between researchers with different taxonomic expertise. Furthermore, Berendt already distinguished between copal and true amber and was aware of the true origin of amber as a fossilized resin of a pine tree. Regardless of the theoretical basis of the time, new species were constantly described and the total number of described species from amber surely exceeds 4860 (Briggs 2018; Ross 2021), most of them being insects.

Far fewer specimens have been reported from copal, with a total of only about 120 species from these resins reported or described from East Africa and Madagascar (Solórzano-Kraemer et al. 2020), for example. Copal has been and still is largely undervalued as a scientific resource (Penney 2010; Penney and Preziosi 2013), although it has great potential for the study of recent biodiversity (Delclòs Martínez et al. 2020; Solórzano-Kraemer et al. 2020, 2022). Indeed, the young age of copal inclusions renders them ideal for documenting the loss of biodiversity, particularly since the colonial and industrial eras. Solórzano-Kraemer et al. (2020) recognized amber as > 2.58 Mya, Pleistocene and Holocene copals as between 2.58–0.0117 Mya and 0.0117 Mya–1760 AD, and Defaunation resin as younger than 1760 AD. Faced with the dual threats of global climate change and global deforestation, the intensive study of copal and Defaunation resin along with extant taxa may be our best and last chance to understand our contemporary biotic communities before it is too late.

Symington Grieve wrote in his book about the great auk in 1885:

The following pages have been written in the hope of interesting some in the story of an extinct bird. The whole history of the Great Auk is a sad one – the continued slaughters of the helpless victims culminating in the final destruction of the race on the skerry, named Eldey, off the coast of Iceland, excites to pity. The last of the Great Auks has lived and died. The race was blotted out before naturalists, when too late, discovered it was gone. Regrets are now useless – the living Garefowl is extinct.

This happened, because of human influence, as it did for at least another 14 vertebrate species in the last 200 years (Piper 2009). One of the most well-known examples of anthropogenic extinction is the marsupial Thylacine (Thylacinus cynocephalus), which was hunted relentlessly to the margins of extinction, till the last one died in 1936 at Hobart Zoo (Brook et al. 2023). Another famous and quite recent event of extinction, not only through hunting, but also due to habitat loss it that of the passenger pigeons (Ectopistes migratorius). Who would have thought that a bird, so common that flock size easily exceeded millions of individuals (Wright 1911), could go extinct? Of course, one key factor was that they were hunted as a food resource, the other on the deforestation, as due to their high specialization in tree nuts, they were not able to find enough food anymore (Guiry et al. 2020). These extinct species, victims of human activities, are today highly valued objects in museums, be it for display, teaching or scientific research.

Humans’ fatal impact on environment extinction is progressing at an alarming rate, with a lot of species going extinct without ever being noticed (McKinney 1999; Régnier et al. 2015). Therefore, copal and Defaunation resin are not only a short window to the past, but they should also be a warning, of what is to come. Defaunation resin in particular is not only amenable to µ-CT analysis, as conducted here (Figs 3, 4, 611, 17), but also to genomic study, at least in some cases (Modi et al. 2021). With so many recent and near recent taxa to describe, let alone true amber fossils, it is imperative that we recognize the value of all biological specimens preserved in collections.

4.2.2. The Samland and Kleinkuhren localities

Samland, or the Kaliningrad Peninsula of today, is located on the south-eastern shore of the Baltic Sea, which has been part of the Soviet Union and Russia since 1945.

One direct locality (PMJ Pa 5827) from the collection is given as Kleinkuhren (in German), today known as Filino, which is located on the north-western tip of Samland. Most specimens contained in the piece were to be very untypical (see sect. 3.1.1. Biotic evidence) for the region of origin on the label, which drove us to further investigate on these localities.

Since the earliest written records of the region, the practice of “Bernsteingräberey” (amber mining or fishing) has been exercised by the inhabitants of the coast of Samland, which they also used to earn their living (Weber 1740; Hildt 1803). In 1861, Karl Mayer described the “faunula of Kleinkuhren”, with 35 specimens to be found in the marine sandstone (Mayer 1861). According to these findings, he assigned the layer to the Rupelian (33.9 and 27.82 Ma). Noetling and A. von Koenen, came to the same conclusion some years later (Meyer 1914). The age of these sediments was questioned, however, and more recent investigations suggest that it is distinctly older, about 48 Ma (Ritzkowski 1997). Nevertheless, Perkovsky et al. (2007) pointed out that the results of Kaplan et al. (1977) are more reliable and suggested 37.7 Ma (Perkovsky et al. 2007), which in retrospect is closer to Mayer. The age estimations of all these researchers clearly indicate that no copal occurs in the sediments of the Samland region. Additionally, we were not able to find any report that copal has ever been found in the region of Kaliningrad-Oblast or its shores.

With the localities “Samland?” or “Samland, Bern-steinwerke Königsberg” and one with an original invoice (see section 3.1.1 above) the question when the collection was acquired could be further clarified. The Preußischen Bergwerks-Hütten-Aktiengesellschaft (Preussag) was founded on December the 13th in 1923; only a few years later they joined forces to form a manufacturing company known as “Staatliche Bernstein-Manufaktur GmbH’ GmbH” (SBM) in 1926 (Erichson and Tomczyk 1998). In 1929, the VEBA (Vereinigte Elektrizitäts- und Bergwerks-AG, Berlin) was established for the uniform financing of the state economic enterprises (Winkler 2019). This indicates that Pa 5863 was purchased between 1923 and 1929. It was not uncommon that amber was sold to entomologists, which was advertised in a timely manner (Königsberg-Pr. 1937). Today, the amount of amber harvested from the Samland peninsula per year was 500 tons in the first decades of the 20th century (Causey 2011).

4.3. Biological conspectus

The primary data that can be captured from fossil organisms ranges from preserved anatomy—whether from sclerites or soft tissue (e.g., Pohl et al. 2010; Boudinot et al. 2022c; Richter et al. 2022)—to chemical composition (e.g., Trueman 2013; Barden et al. 2017; McCoy et al. 2017), with the two sources of information being nearly indistinguishable depending on the tools used and the scale of comparison (e.g., Modi et al. 2021; Jiang et al. 2022). In order to maximize the biological value of fossils, it is essential to identify the geological source unambiguously and to critically evaluate the plausible phylogenetic affinities of the inclusions. While the former requires the tracking or retracing of stone provenance often coupled with chemical tests (e.g., section 3.1.1 above and 4.3.2 below), the latter depends on: (1) the phylogenetic stability of the taxonomic system in question; (2) the quality of anatomical information obtained from the specimen; and (3) the availability of comparable information from extant taxa. In best case scenarios, both the phylogeny and phenotypic affinities of the fossils may be evaluated jointly (e.g., Klopfstein and Spasojevic 2019; Mongiardino Koch and Thompson 2021; Boudinot et al. 2022a) or in sequence, which nearly always requires substantial revision of fossil interpretations (e.g., Fikáček et al. 2020; Boudinot et al. 2022d; Schädel et al. 2022). A special issue of contemporary paleontological phylogenetics is to produce a classification that is both robust and systematically organizes diagnostic information, allowing future works to place fossils with certainty, or at least explicit uncertainty. Below, we highlight both issues via discussion of the Psocodea (section 4.3.1), which are grossly understudied anatomically, and Dorylus (section 4.3.2), which have been plagued by taphonomic uncertainty for over a century. We conclude this section with a consideration of broader issues and methods for paleoentomology (section 4.3.3).

4.3.1. The case of barklice (“Psocoptera”), an underestimated and undeservedly spurned group

The barklice, or the psocopteran grade of the order Psocodea, are in a twilight zone of phylogenetic paleontology, as fossil material is very abundant from the present through the Mesozoic, yet the extant taxa are grossly understudied anatomically (Yoshizawa 2002; Mockford 2018; Kawata et al. 2022). Moreover, only the sub- and infraordinal relationships have been resolved via molecular systematics (de Moya et al. 2021), with the exception of a few families (Mockford 1999; Yoshizawa and Johnson 2008). As a consequence, a well-founded system to place fossils is lacking. The morphological assumptions of prior generations of taxonomists are largely untested, hence still dominant in the process of taxonomic determination and evolutionary inference. This is in addition to being problematic for understanding Psocodea for their own sake. This reduces the phylogenetic key role of the group as either sister to the Holometabola or the Condylognatha (Misof et al. 2014), which are issues of crucial importance to broader insect phylogenetics and evolutionary history.

Two extinct taxa directly highlighting the present difficulties of psocodean systematics are †Arcantipsocus and †Paramesopsocus, both originally placed in new, nominotypical families (Azar et al. 2008, 2009), and now considered to belong to Amphientomidae and Electrentomidae, respectively (Mockford et al. 2013). In both cases, the authors relied on the cladistic analysis of Yoshizawa (2002) for morphological characters. Azar et al. (2008, 2009) recognized that the taxonomic sampling of Yoshizawa (2002) was focused on Psocomorpha. Nevertheless, they placed their fossils using the characters of that study as the matrix was the most comprehensive that was available. As a consequence, both paleontological studies attributed the fossils to Psocomorpha, with overreliance on the thick pterostigma and presence of the nodus, which were considered as autapomorphies of the suborder (Yoshizawa 2002). By studying an expanded sample of fossil and extant taxa, Mockford et al. (2013) recognized that these characters are homoplastic among the suborders, and that other, less prominent features reasonably place †Paramesopsocus near Amphientomidae and †Arcantipsocus within this family. Even though this is certainly an improvement, these placements have yet to be incisively scrutinized using adequate data sets and analytical methods.

Both examples underline the problems with placing fossils into insufficiently founded systems, where relationships are often not supported by well-defined apomorphies, or where assumptions have yet to be tested. A specific problem in psocodean systematics is the almost exclusive use of characters of wing venation and genitalia, while most other body parts or organs are understudied and neglected during investigations. In a comparative sense, it is surprising that the shape and presence or absence of sclerites (except for genital structures) are very rarely used in systematic research on Psocodea, in contrast to other groups or insects (see, e.g., Pohl and Beutel 2005; Beutel et al. 2011). They are often the best-preserved characters in amber fossils besides the wings and might provide many phylogenetically informative features. It is conceivable that the missing access to new technologies may impede scientific progress in this field. Moreover, many fossils are simply not sufficiently preserved for detailed observation. With our present work, we hope to ignite interest in a more thorough morphological analysis of extant and fossil Psocodea, particularly using modern morphological methods such as µ-CT and computer rendering, which can reveal rich morphological data from limited material (Figs 711).

4.3.2. The case of Dorylus, a long historical arc

Ants of the genus Dorylus dominate Old World tropical ecosystems above and below ground, where they occur, and have long fascinated and challenged systematists working on ants (Gotwald 1995; Borowiec 2016; Boudinot et al. 2021). As such, the geological age and paleogeographic distribution of their crown clade is of considerable interest. Any fossils potentially attributable to Dorylus are thus of substantial evolutionary importance. In the present study, we identified one such species represented by dozens of individual specimens preserved in resins labeled as “Baltic amber” from the PMJ Pa collection (Figs 2, 3). The temptation to accept this assumption as a conclusion was powerful, yet we struggled to make sense of the initial qualitative tests. We therefore sent samples of the resin matrix for FT-IR, which contradicted the hypothesis that these specimens were from Eocene-aged succinite. Still not satisfied, we subjected one quality exemplar of this Dorylus species to SR-µ-CT scanning and 3D reconstruction (Appendix 1: Fig. A1).

With our µ-CT data, we were able to identify the PMJ Pa Dorylus as belonging to the extant subspecies Dorylus nigricans molestus, based on the key to subgenera from Gotwald (1982) and the key to the D. nigricans species group (former Anomma) of Santschi (1912). Specifically, the fossil has 11-merous antennae with flagellomeres that are longer than wide, the terminal abdominal tergum has well-defined ridges around its central depression, the spines of the frontal carinae and posterolateral corners of the head are lacking, the petiole widens posteriorly as seen in dorsal view, and the ventral posterolateral corners of the node angular and produced, rather than rounded. Coupled with the identification of the synincluded platypodine as a member of an extant metapopulation, we were forced to reject the succinite hypothesis. Subsequent 14C analysis resulted in an estimated age of ~145 years for the D. n. molestus-bearing piece, squarely falling in the category of Defaunation resin. Although these specimens are not as ancient as we were led to believe by the original labels, they may yet be of systematic value: To resolve the species boundaries of this complex, a comprehensive revision of Dorylus nigricans integrating sequence and morphological data is necessary (see Wilson and Brown 1953 on subspecies in myrmecology and Borowiec 2019 for further consideration in the context of Dorylinae).

The PMJ Pa D. n. molestus are far from the first positive subfossil members of Dorylus and the first false positive Dorylus from Baltic amber. Alongside the doryline Neivamyrmex iridescens from Colombian copal, DuBois (1998) previously reported D. n. molestus from confirmed East African copal sensu lato. Over a century before, F. Smith (1868) had identified a Dorylus (“being either Anomma rubella or a closely related species”, p. 184) from what he assumed to be Baltic amber, but which was later determined to be East African copal (Grimaldi et al. 1994; O’Hara et al. 2013). Notably, “Anomma rubella” is currently considered to be Dor. nigricans rubellus (Savage, 1849), which suggests that the imperfect F. Smith may have handled material quite similar to, if not from the same source, as that of the PMJ Pa and those cited by DuBois (1998). Even more recently, Solórzano-Kraemer et al. (2022) figured multiple unidentified Dorylus specimens from Holocene copal (= Defaunation resin) from Tanzania (their fig. 11e, f), while the unavailable name †Dissumulodorylus perseus was provided for specimens of putative Baltic origin (Sosiak et al. 2022), which were later revealed via FT-IR to be sub-fossil resin by those authors (Sosiak et al. 2023a, b). Although moot due to unavailability, which we maintain, key structural details for species-level identification were not visible in their scans even after refined segmentation (Dubovikoff and Zharkov 2023). The work of Sosiak et al. (2022, 2023a, b) is an exemplary demonstration of biological hypothesis testing, and further underscores the necessity for a critical approach to the use of “amber” fossils for systematics and evolutionary influence.

4.3.3. Fossil evaluation: Further pitfalls

The two direct examples arising from the main part of this study illustrate the dual difficulties and importance of correctly identifying fossil provenance (section 4.3.2) and placing fossils in systems, when robust phylogenetic and anatomical documentation is lacking (section 4.3.1). With the deep and expanding backlog of amber fossils from Eocene Baltic and other sources (e.g., Peris et al. 2016; Delclòs et al. 2023), a true flood has become available with the intensive exploration of Burmese Kachin amber (e.g., Ross 2019, 2021; Boudinot 2020; Boudinot et al. 2020; Peris and Rust 2020; Pohl et al. 2021; Beutel et al. acc. pend. minor revision), all of which necessitates critical care in the treatment of anatomical information from these and other fossils, including adpression fossils, which may be older but are usually less well-preserved (e.g., Boudinot et al. 2022b). In addition to inadequacy of the phylogenetic system (point 1, section 4.3.1), insufficient morphological documentation (point 2, section 4.3.1), and failure to compare fossils to extant taxa (or absence of comparable information; point 3, section 4.3.1), we recognize three more shortcomings that, in variable combination, may lead to problematic inferences: (4) lack of taxonomic and evolutionary context, e.g., no keys, character lists or data matrices are provided; (5) inexpert knowledge of potentially related extant groups; and (6) inadequate phylogenetic evaluation. Because the literature is rapidly being filled with incautious conclusions, which are hard to correct, we find it unfortunately necessary to outline these issues and some examples so as to encourage finer comparative attention to detail.

The erroneous conclusions of two examples may have been emolliated via taxonomic specialist contribution (e.g., Li et al. 2022; see also Vitali 2019). Critical reevaluation of a putative mordellid larva from Cretaceous amber (Zippel et al. 2022) found that the insect in question is a sawfly (Batelka and Engel 2022), possibly belonging to the family Blasticomidae (Rasnitsyn and Müller 2023), while putative “triungulins” of Strepsiptera (Schawaroch et al. 2005) were eventually correctly placed based on piecemeal reconstruction of fine structures (Beutel et al. 2016, Batelka et al. 2019) with the final clarification provided by Pohl et al. (2018), wherein the first true strepsipteran primary larva enclosed in amber was identified. A third example, that of the putative new beetle family †Ptismidae (Kirejtshuk et al. 2016), was recognized as a synonym of the scirtiform family Clambidae after it was shown that this taxon was defined based on symplesiomorphies and gross rather than specific, structural similarities (Cai et al. 2019). As in many “high throughput” studies on amber fossils, the documentation and interpretation of morphological features were insufficient.

Beyond problems of nomenclature and systematics, lack of precise observation and identification may also lead to evolutionary misinterpretations that may have ramifying consequences for paleoecology. For example, there are presently only few events of pollination documented in the fossil record of the Cretaceous and Cenozoic and these should be taken with caution (e.g., Peña-Kairath et al. 2023). A new species of the cucujoid family Kateretidae was described by Tihelka et al. (2021), who suggested that the beetle was feeding on angiosperm pollen and was acting as a pollinator, thus seemingly revealing a very early event on beetle-angiosperm interaction. However, it was shown by Bao et al. (2022) that the pollen in question was in fact of gymnosperm origin and not ingested by the beetle via careful documentation and experimental replication of pollinivory.

An apparent and frequent problem in insect paleoentomology are fossil placements based more-or-less on intuition (e.g., Kirejtshuk et al. 2016; Kirejtshuk 2020), rather than arguments in the sense of synapomorphies or formal phylogenetic analyses based on maximum parsimony (MP) or Bayesian inference (BI). The placement of adpression fossils was formally evaluated by Fikáček et al. (2020) and Boudinot et al. (2022d), using morphological data sets and phylogenetic topologies based on comprehensive molecular data sets. A similar approach was recently applied to minute myxophagan beetles in Burmese amber (Fikáček et al. 2023). The characters were analyzed in a Bayesian framework under different schemes of constraints, also using phylogenetic patterns based on molecular phylogenies. It is still a common practice in paleoentomology to erect and shift extant or extinct taxa without adequate analyses or at least phylogenetic arguments in the sense of apomorphies (e.g., Kirejtshuk 2020). However, this approach leads to random taxonomic and phylogenetic changes, lacks a solid basis, and does not help to understand the evolution of beetles and other groups (e.g., Fikáček et al. 2020; Boudinot et al. 2023).

4.4. Technological Conspectus: Phenomics

A key technology transforming the study of insect anatomy and evolution is micro-computed tomography (µ-CT), which allows for the non-destructive, replicable, quantitative sampling of structures at the submicron scale either preserved or in motion, in the case of x-ray kinematics (or cineradiography, e.g., van de Kamp et al. 2015; Wulff et al. 2017). The non-invasive generation of phenomic data further allows for the evaluation of complex functional interactions, such as for the metasoma of Scorpiones (Günther et al. 2021) and copulation in Strepsiptera (Peinert et al. 2016; Jandausch et al. 2023), Hymenoptera (Semple et al. 2021), and Lepidoptera (Zlatkov et al. 2023). For the purposes of paleoentomology, µ-CT has profound advantage as beam penetrance allows for the discovery of biological inclusions in opaque amber (Lak et al. 2008), phosphatized nodules (van de Kamp et al. 2018), and even Triassic coprolites (Qvarnström et al. 2021). In a pair of studies on Cretaceous stem ants (Boudinot et al. 2022c; Richter et al. 2022), it was discovered that soft tissue may be preserved in spectacular detail, including a nearly complete cephalic muscle set, glands, and elements of the central nervous system, and the utility of µ-CT was demonstrated for revisionary systematics and phylogenetic character discovery. That µ-CT is especially valuable for character discovery and phylogenetic hypothesis testing was also demonstrated in a study on the prosternum of extant Hymenoptera (Boudinot et al. in prep.), which expanded the available anatomical variables of this structure from 11 to 124. This study further showed potential for µ-CT as a tool for museomics, as a century-old specimen produced high-quality scan data, complementing genome capture from preserved material (e.g., Blaimer et al. 2016). Although relatively time-consuming, even simple surface renders may be highly informative (e.g., Garcia et al. 2019; Jałoszyński et al. 2020), especially for rare taxa or irreplaceable specimens (e.g., Simonsen and Kitching 2014) and when used as one prong of a multi-modal approach for phenotype documentation, alongside green-fluorescent light for fossils (e.g., Clarke et al. 2018; Boudinot et al. 2020, 2022c), and SEM, CLSM, and manual histology for extant taxa (e.g., Richter et al. 2019, 2023; see also Friedrich and Beutel 2008, Friedrich et al. 2014).

Even though the loss of information and amount of artefacts are usually very low, some aspects must be taken into account: (a) depending on fixation considerable deformation can occur, as for instance tissue preserved in ethanol can shrink through dehydration, depending on time and tissue properties up to a loss of 60% of the original volume (Hedrick et al. 2018; Leonard et al. 2022); (b) imaging contrast can be distinctly improved by iodine-staining (Metscher 2009) but this can demineralize specimens immersed for a longer time span (Early et al. 2020); (c) stained specimens can be de-stained very efficiently using thiosulfate solution, but this can increase calcium solubility and cause decalcification (Mataic and Bastani 2006; see Callahan et al. 2021 for a de-staining protocol); (d) desktop micro-CT scanners are still expensive and energy consuming, and not accessible for all scientists; (e) the post-processing of the data can be very time consuming; and (f) in the case of most synchrotron-scanned resin pieces a dark band occurs where the beam passed (e.g., Pohl et al. 2019; Sadowski et al. 2021), consequently thus it is also preferable that the piece should be carefully documented with photographs before scanning. Care should always be taken not to use an excessive level of energy of synchrotron radiation, as this can be destructive or leave behind an irreversible brownish band to the amber. The documentation of structural details can be enhanced by isolating individual structures of a certain specimen through physical preparation, or using an intact specimen; the target focal areas can be cleaned with chloroform (Ammar et al. 2015). Moreover, appropriate cleaning can distinctly reduce artifacts and thus accelerate the further processing. This can be further optimized with AI, for instance by using Biomedisa (Lösel et al. 2020).

Another major advantage of µ-CT data is that they can be made available to the community in suitable databases. A specimen gone through the three steps mentioned above can be distributed to scientists or the public in various forms. The data accessibility is crucial in different ways, but especially so for museum material and type specimens (Faulwetter et al. 2013), with cybertypes having use even beyond classificatory purposes (e.g., Naumann et al. 2020). For many active researchers, access to type material is often very difficult (Orr et al. 2020). Shipping is expensive and bears an enormous risk of damage or even losing specimens. In most cases, the scientific benefit and the entitlement of scientists to study the fauna of their country outweighs this risk (Dupérré 2020). However, µ-CT data can be made available electronically and thus open a new dimension of making specimens accessible, in the ideal case even including surface textures and color (Ijiri et al. 2018). Even though digital information can never fully replace the physical type specimens (Rogers et al. 2017), it is a highly efficient way to facilitate revisions and also to stimulate scientific inquiry and discussion in different contexts. Even if technical resources are limited, this can be extended using models from platforms like Sketchfab (Epic Games, Cary, North Carolina, USA) or MorphoSource ( In our study as well as in previous contributions (Aibekova et al. 2022; Tröger et al. 2023; Weingardt et al. 2023), these options were used to visualize complex 3-dimensional structures in an easily accessible way to contribute to a better understanding of insect morphology.

A final aspect of µ-CT data that confers unique advantage is for museums- and classroom-based pedagogy (e.g., Shelmerdine et al. 2018). School children and students can examine, disassemble, and assemble a wide variety of objects which enhances the understanding of complex 3D objects. The risk of damage is negligible compared to real specimens or wax models. This has been successfully demonstrated with the neurocranium of the mud-shark Squalus acanthias at the Institute of Zoology and Evolutionary Research of the Friedrich Schiller University (Jena, Germany) (Moritz pers. comm., 2022). 3D reconstructions are further advantageous as they can be scaled, which facilitates the visualization of structures or even entire animals which are otherwise hardly accessible. In the current project EntomonVR (Saqalaksari et al. 2023) demonstrated new opportunities to study and enhance the understanding of insect morphology in an engaging and appealing way. A less expensive way to present µ-CT results as 3D printed models was used in the exhibition of the Phyletisches Museum, where a copulating pair of leaf beetles (Neocrepidodera ferruginea) is on display, which was magnified forty times and airbrushed. With the above mentioned combination, a multisensory approach in museums can be boosted, as it is possible to conserve valuable objects, while allowing visitors to simultaneously handle an authentic copy (Wilson et al. 2017; Ziegler et al. 2020). This includes the option to make objects tangible for visually impaired visitors (Neumüller et al. 2014). The use of CT-scans to create highly realistic enlarged models of different organisms is now gaining great momentum, as for instance demonstrated by 10TONS ( or Julia Stoess (

5. Conclusion

The only direct documentation of the history of evolution in the dimension of time is the fossil record, for which the highest fidelity of preservation is afforded by exuded resins that may fossilize over the course of millions of years, thus forming amber. To be useful for biodiversity studies, it is critical that the source of inclusion-bearing resins be identified, as the difference in age between true amber and copal or Defaunation resin may profoundly influence ecological, biogeographical, and evolutionary inferences. The rediscovered amber collection of the Phyletisches Museum allowed us to starkly demonstrate this crux, as several pieces labeled as Baltic amber would have represented new generic records for the ant fauna of the Eocene, including the widespread and dominant genera Crematogaster, Dorylus, Lepisiota, and Pheidole. Through chemical (FT-IR, UV-VIS, 14C), systematic (anatomical SR-µ-CT reconstruction), and historical investigation, we were able to not only correct the historical mislabeling of these and all other specimens in the amber collection, but to also review and revise the fossil record of Amphientomum and the Amphientomidae (Psocodea), several clades of Formicidae (Camponotini, Crematogaster, Dorylinae, Pheidole, Plagiolepidini, †Yantaromyrmex), the Nevrorthidae (Neuroptera), and two beetle genera (Doliopygus, Platypodinae; †Baltistena, Mordellidae). With respect to fossil resin provenance, we found that the study of historical records is highly useful where these exist, and that the generally recommended qualitative tests for amber identity fail spectacularly when benchmarked against quantitative tests, particularly FT-IR. In brief, when new records of taxa that are millions to tens of millions years older than the oldest known representative, great care should be taken to ensure that label data accurately reflect the source of the fossil material. With the rediscovered Bernsteinsammlung, the Phyletisches Museum is now known to comprise Defaunation resin, copal, and succinite (true Baltic amber) as well as Kachin amber. The biological value of subfossil material should not be overlooked.

Conflicts of interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; nor in the decision to publish the results.

Author contributions

Conceptualization: BEB, BLB. Methodology: BEB, BLB, MW, DT, KJ, JUH, HP. Software: JUH. Validation: BEB, BLB. Investigation: BEB, BLB, MW, DT, KJ, JUH, DL, OTDM, JB, AR. Resources: JUH. Data Curation: BEB, BLB, MW, JUH, JB. Writing, original draft: BEB, BLB, DT, MW, JB, DL. Writing, review & editing: RGB, AR, HP. Visualization: MW, DT, BLB. Supervision: RGB, HP. Project administration: BEB, BLB. Funding acquisition: BEB, DT, MW, AR.


This research was funded by the following.

  • Boudinot: the Alexander von Humboldt Stiftung via a research fellowship (2020–2022) and a Peter S. Buck research fellowship at the Smithsonian Institute (2023).
  • Richter: the Evangelisches Studienwerk Villigst eV via a scholarship (2020–2022).
  • Förderverein Phyletisches Museum Jena e. V.
  • Research of Jan Batelka was financed from operational program „Grant Schemes at CU “(reg. no. CZ.02.2.69/0.0/0.0/19_073/0016935).
  • Tröger: scholarship of the Deutsche Bundesstiftung Umwelt (DBU) (2022–)
  • Weingardt: Landesgraduiertenstipendium (2023–), Honours Programme University of Jena 2021–2022

Data availability statement

The original μ-CT datasets of ‡Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov. (PMJ Pa 5809), Archipsocidae gen. et sp. indet (PMJ Pa 5825), †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (PMJ Pa 5870), Doliopygus cf. serratus (PMJ Pa 5827), Dorylus nigricans molestus (PMJ Pa 5884), and the neotype of ‡Pheidole cordata (PMJ Pa 5889) are databased and assigned a unique identifier at the Phyletisches Museum (Jena, Germany) and additionally available at the data repository MorphoSource (URL: with the reference numbers: 000549407 (†Amphientomum knorrei Weingardt, Bock & Boudinot, sp. nov.), 000549379 (Archipsocidae gen. et sp. indet.), 000549353 (Dorylus nigricans molestus), 000549006 (†Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov.), 000548650 (Doliopygus cf. serratus), 000552612 (†Pheidole cordata Holl 1829, neotype).


We thank: Dietrich von Knorre and Matthias Krüger for sharing their profound knowledge of the whole PMJ collection; the International Amber Association (IAA) Gdańsk, Poland for chemical analysis; Brian Fisher, Michele Esposito, and Barry Bolton for AntWeb and AntCat; Charles Lienhard, Lulan Jie, Gurusamy Ramesh, Alexander Rasnitsyn, Christian Schmidt, and Dmitry Vassilenko for sharing Psocodea literature; Vincent Perrichot for loaning Ethiopian amber material; Feiyang Liang for confirming the genus identification of Amphientomum and providing additional information on amphientomid genitalia; Phil Ward and Rodolfo da Silva Probst for discussing the ideal treatment of the camponotine fossils; Alêxandre Ferreira for discussing the Defaunation resin Pheidole; Bjarte Jordal for identification of the platypodine, provision of literature, and discussion of Doliopygus systematics; Eva-Maria Sadowski, David Ware, and Andreas Abele-Rassuly for the possibility to take photographs at the MfN Berlin; and Jill Oberski for providing comment on a pre-submission version of the MS and for consistent discussion during the construction and revision of the work. We also thank Kazunori Yoshizawa and Phil Ward for their incisive and useful feedback on the manuscript, as well as the editor, Sonja Wedmann; we thank Phil once more for catching an embarrassing blunder, for which we are grateful.

We acknowledge the provision of beamtime related to the proposal BAG-20190010 at PETRA III beamline P05 of DESY, a member of the Helmholtz Association (HGF). We acknowledge the support during the beam times by Hereon team members Fabian Wilde, Julian Moosmann, and Felix Beckmann. This research was supported in part through the Maxwell computational resources operated at Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany. Gunnar Brehm for the loan of his lepiLED. Additional support was provided by the Alexander von Humboldt Stiftung (BEB: 2020–2022; the Japan Society for the Promotion of Science (AR: 2023–), the Smithsonian Institute (BEB: 2023), Landesgraduiertenstipendium (MW: 2023–), the Honours Programme from University of Jena (MW: 2021–2022), the Evangelisches Studienwerk Villigst eV (AR: 2020–2022), the Deutsche Stiftung für Umwelt (DT 2022–), the Grant Schemes at Charles University (JB: reg. no. CZ.02.2.69/0.0/0.0/19_073/0016935), Susanne & Jens Wurdinger and the Förderverein Phyletisches Museum e.V.. We are very grateful to the Smithsonian’s Biodiversity Heritage Library and the librarians who kindly permitted us to examine an original book (Schweigger 1819) and scanned the pages: Leslie Overstreet and Erin Rushing. Last but not least, we thank the Museum für Naturkunde (Berlin) for waiving the publication costs of our article.


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Appendix 1

Figure A1. 

Model 1 of Dorylus nigricans molestus (Formicidae: Dorylinae) preserved in piece PMJ Pa 5884. An interactive version of this model is available in the HTML version of this article online and on Sketchfab: URL:

Figure A2. 

Model 2 of Doliopygus cf. serratus (Curculionidae: Platypodinae) in piece PMJ Pa 5827. An interactive version of this model is available in the HTML version of this article online and on Sketchfab: URL:

Figure A3. 

Model 3 of the holotype specimen of ‡A. knorrei Weingardt, Bock & Boudinot, sp. nov. (Amphientomidae: Amphientominae) preserved in piece PMJ Pa 5809. An interactive cybertype is available in the HTML version of this article online and on Sketchfab: URL:

Figure A4. 

Model 4 of Archipsocidae gen. et sp. indet. preserved in kaori gum piece PMJ Pa 5825. An interactive version of this model is available in the HTML version of this article online and on Sketchfab: URL:

Figure A5. 

Model 5 of the neotype of ‡Pheidole cordata Holl, 1829 preserved in copal piece PMJ Pa 5889. An interactive cybertype is available in the HTML version of this article online and on Sketchfab: URL:

Figure A6. 

Model 6 of the holotype of †Baltistena nigrispinata Batelka, Tröger & Bock, sp. nov. (Mordellidae) preserved in piece PMJ Pa 5870. An interactive cybertype is available in the HTML version of this article online and on Sketchfab: URL:

Supplementary materials

Supplementary material 1 

Amber and copal specimens of the Phyletisches Museum collection

Brendon E. Boudinot, Bernhard L. Bock, Michael Weingardt, Daniel Tröger, Jan Batelka, Di LI, Adrian Richter, Hans Pohl, Olivia T. D. Moosdorf, Kenny Jandausch, Jörg U. Hammel, Rolf G. Beutel

Data type: docx

Explanation note: Amber and copal specimens of the Phyletisches Museum collection sorted by inventory number with the number of pieces given for each, what source they had according to the label and what source they are after identifying.

This dataset is made available under the Open Database License ( The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (39.81 kb)
Supplementary material 2 

Protocol of the IAA

Brendon E. Boudinot, Bernhard L. Bock, Michael Weingardt, Daniel Tröger, Jan Batelka, Di LI, Adrian Richter, Hans Pohl, Olivia T. D. Moosdorf, Kenny Jandausch, Jörg U. Hammel, Rolf G. Beutel

Data type: pdf

This dataset is made available under the Open Database License ( The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (275.35 kb)
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