The authors searched Web of Science and Google Scholar in Spanish and English using combinations of terms including “Chile,” “fossil insects,” “fossil beetles,” “plant–insect interaction,” “aDNA” and “Chironomidae.” They assessed books, book sections, peer-reviewed articles, theses and conference contributions, classifying publications as primary reports or secondary sources and citing original records rather than later compilations. Their broad definition of fossil evidence included impressions, inclusions, preserved carcasses, ancient DNA, plant–insect interactions and other traces.

Primary research is geographically concentrated in south-central Chile. Los Lagos has the most studies, with 16, chiefly focused on the Pilauco site dated to approximately 16,500–12,700 years before present. Magallanes and La Araucanía each have five studies, while Arica y Parinacota has four and Coquimbo three. The review attributes this distribution to differences in research attention and the availability of suitable fossil-bearing localities.

The temporal record is similarly uneven. Forty-one primary studies concern the Quaternary, especially the late Pleistocene and Holocene, and largely involve Coleoptera and Diptera, including Chironomidae preserved in lake sediments, peat and rodent middens. Seven studies cover the Triassic, seven the Cretaceous and seven span multiple periods. The Paleozoic record is limited to trace fossils from two localities, with no continental arthropod body fossils reported.

Triassic body-fossil records include the beetles Ischichucasyne santajuanaensis and Ademosyne sp., both assigned to the extinct family Permosynidae, and the hemipteran Bandelnielsenia chilena, assigned to Dysmorphoptilidae. These imprints come from the Carnian–Norian Santa Juana Formation, dated to 237–201 million years ago. Two Paleoovoididae ichnospecies, Paleoovoidus contactus and Paleoovoidus megaovoidius, were recorded from Norian deposits of the La Ternera Formation and associated with odonate egg-laying scars on fossil leaves.

Cretaceous evidence includes the beetle Doroteus guidensis from the Maastrichtian Dorotea Formation and Australocerambyx chilensis, the first ichnotaxon documented from Chile. The latter was described from galleries in petrified wood attributed to a cerambycid-type beetle larva, probably in a gymnosperm trunk. Its geological age remains uncertain, although geographic proximity supports a provisional Cretaceous attribution. Cretaceous deposits on Nelson Island also preserve galls and leaf-mining traces in Nothofagus leaves.

The Quaternary literature is dominated by studies of fossil beetles and chironomids. Work at southern Chilean sites, including Rupanco, Puerto Octay, Puerto Varas, Dalcahue and Río Caunahue, documented assemblages containing species with living counterparts. Older assemblages included insects associated with southern forests and northern Patagonian tundra, whereas assemblages younger than 14,500 years before present contained components typical of the Valdivian temperate rainforest. At Monte Verde, near Puerto Montt, an insect assemblage from approximately 15,000 years before present indicated environmental and temperature conditions comparable with those of the present day.

Three dung beetle taxa were described from Upper Pleistocene deposits at Pilauco: Onthophagus pilauco, Scybalophagus brellenthinae and Gomphocopris ashworthi. O. pilauco was reported as the southernmost record of its genus in the Americas, while S. brellenthinae was considered a third Chilean species and presumed extinct. The authors suggested that the local extinction of these dung specialists accompanied the loss of large mammals because their developmental substrate diminished.

The checklist found Coleoptera to be the most family-diverse insect order, with 53 families represented; Curculionidae, Carabidae and Staphylinidae had 64, 34 and 33 records, respectively. Chironomidae accounted for 55 records. Many entries remained indeterminate at finer taxonomic levels, reflecting limitations in specimen identification, preservation and taxonomic assessment. The review also questioned several historical records, including Schweigger’s purported Chilean copal inclusions, an insect interpretation of a mollusk from the Los Molles Formation, and insect remains reported from the Navidad Formation that later authors considered probable contaminants.

Repository information was incomplete. Thirty-seven studies specified where studied material was housed, while 25 did not. The Museo Nacional de Historia Natural de Chile and Museo Pleistocénico Chuyaca were each cited nine times, and international repositories also held studied material. The authors identified understudied regions, incomplete ichnotaxonomic work and inconsistent curatorial information as major limitations, and called for broader exploration, modern re-examination of known localities, accessible databases and recognized repositories for Chilean fossil insects and allied arthropods.

Subject of Research: Systematic review and checklist of Chile’s fossil insects, arachnids and myriapods

Article Title: Fossil insects of Chile, including arachnids and myriapods: a systematic literature review and checklist

Article References: Tello, F., Nieto, A., Martel-Cea, A., Lara, M. B., & Moisan, P. (2025). Fossil insects of Chile, including arachnids and myriapods: a systematic literature review and checklist. Fossil Record, 28(2), 485-509. https://doi.org/10.3897/fr.28.168711

Image Credits: AI Generated

DOI: 10.3897/fr.28.168711

Keywords: fossil insects, Chile, paleoentomology, systematic review, arthropod fossils, trace fossils, Quaternary fossils, Triassic fossils, Cretaceous fossils, fossil collections, Fossil, insects

The researchers identified one frog trunk vertebra as Duttaphrynus melanostictus and assigned snake vertebrae to Lycodon rufozonatum, Ptyas mucosa, Ptyas cf. mucosa and Protobothrops sp. Six additional fragmentary snake vertebrae were assigned to Alethinophidia indeterminate, while two caudal vertebrae were identified only as Colubridae indeterminate. Because the material consists largely of isolated and incomplete vertebrae, several assignments remain conservative.

Taiwan occupies a transitional zone between the Palearctic and Indomalayan biogeographic regions. Its mountainous topography, latitudinal position and varied climate have contributed to high levels of endemism among terrestrial vertebrates. Excluding marine species, the island supports 37 native amphibians and 85 reptiles, including 14 endemic frogs, 18 endemic lizards and 14 endemic snakes.

Before this assemblage, the absence of Taiwanese herpetofaunal fossils left it unclear whether modern diversity and endemism reflected recent dispersal, long-standing lineage persistence across glacial and interglacial cycles, or a combination of these processes. The new specimens offer direct evidence for the former presence of widely distributed lineages, but they do not by themselves establish the complete history of colonization or persistence.

The fossils were collected from reworked surface deposits in the bed of the Tsailiao River. Most fossils in the area lack precise stratigraphic positions because seasonal flooding transports and mixes them, although many are generally attributed to the nearby Chiting Formation. The formation is approximately 2,000 metres thick and consists mainly of interbedded sandstones, siltstones and mudstones deposited through marine transgression–regression cycles with substantial fluvial and terrestrial influence.

Fossils from the Kuoling and Takengwei members are dated to approximately 0.7–0.4 million years ago through nannobiostratigraphic analyses and cyclostratigraphic estimates. In view of the uncertain provenance of the herpetofaunal specimens, the researchers conservatively used the Chiting Formation’s broader age range of approximately 0.8–0.4 million years. The material was collected over three decades by Liang-Chieh Wang and recovered through simple sieving and manual sorting.

Taxonomic identification relied on morphological comparisons with published descriptions, fossil material and reference vertebrae from extant animals housed at the Biodiversity Research Museum, Academia Sinica, Taiwan. Specimens were photographed with a stereomicroscope and digital camera, and the images were focus-stacked and digitally optimised. Measurements were taken where preservation allowed, and the researchers also quantified vertebral vaulting. All examined fossils are housed at the museum under the registration code ASIZF.

The amphibian specimen was a trunk vertebra longer than 4.5 millimetres. Its flattened, dorsoventrally compressed centrum supported identification as Duttaphrynus melanostictus rather than Bufo bankorensis, whose centrum is more elevated in lateral view. Among the snakes, two trunk vertebrae were identified as Lycodon rufozonatum, including characters such as tall neural spines, deep subcentral grooves, distinct subcentral ridges and a depressed neural arch. One vertebra was confidently assigned to Ptyas mucosa, while two additional specimens were identified as Ptyas cf. mucosa; the latter assignment remained tentative because poor preservation, including the possible loss of epizygapophyseal spines, prevented a definitive determination.

One vertebra was classified as a crotaline viperid and compared most closely with Protobothrops or Trimeresurus rather than Gloydius. Its short, wide form, thick hypapophysis arising near the middle of the centrum, and large cotyle and condyle supported placement within Crotalinae. The fossil was larger than a comparative adult Trimeresurus stejnegeri vertebra and differed from the only living Protobothrops species in Taiwan in the form of its prezygapophyseal accessory processes, so the researchers retained the conservative genus-level identification of Protobothrops sp.

The co-occurrence of Duttaphrynus, colubrids and a viperid was interpreted as consistent with a warm, humid landscape containing water bodies, riparian corridors, moist open woodland and forested terrain. The frog was associated with nearby freshwater or semi-aquatic environments; Lycodon and Ptyas with moist open woodland or ecotones near water; and Protobothrops with a varied landscape mosaic. This reconstruction agrees with earlier evidence from terrestrial vertebrate fossils and the formation’s depositional setting, although the specimens may not represent a strictly coeval community.

The assemblage documents low-elevation lineages that remain present in Taiwan, including Duttaphrynus, Lycodon, Ptyas and Protobothrops. Its occurrence is consistent with genetic hypotheses concerning the persistence of broadly distributed Oriental taxa through East Asian sea-level oscillations, but it does not establish that each lineage persisted continuously on the island. The absence of more northerly Palearctic or southerly tropical lineages may reflect the assemblage’s regional setting and limited sampling. The authors state that expanded surveys across Taiwan and adjacent areas will be essential for clarifying the composition of Quaternary herpetofauna and testing the island’s multi-source, multi-pulse biogeographic history.

Subject of Research: Middle Pleistocene amphibian and snake fossils from southern Taiwan

Article Title: First fossil frog and snake assemblage from southern Taiwan: a window into Pleistocene herpetofauna and palaeoenvironments in subtropical East Asia

Article References: Lin, C.-H., Lin, S.-M., Chien, C.-W., Lin, T.-E., Nazir, H., & Singh, N. P. (2025). First fossil frog and snake assemblage from southern Taiwan: a window into Pleistocene herpetofauna and palaeoenvironments in subtropical East Asia. Fossil Record, 28(2), 293-308. https://doi.org/10.3897/fr.28.164568

Image Credits: AI Generated

DOI: 10.3897/fr.28.164568

Keywords: Taiwan palaeontology, Middle Pleistocene, fossil herpetofauna, frog fossils, snake fossils, Chiting Formation, Tainan, palaeoenvironment, vertebrate biogeography, First, fossil, frog

The achievement, published in the journal Fossil Record, matters because cricket wings are notoriously difficult to interpret in fossils. Most ancient insects survive only as flattened imprints in rock, and even the lucky specimens preserved in amber often have incomplete wings or veins whose trajectories are impossible to follow. In Picogryllus carentonensis, the right forewing is damaged, but crickets habitually fold their right wing above the left one, so the left forewing underneath was almost fully complete. The team used propagation phase-contrast X-ray synchrotron microtomography at the European Synchrotron Radiation Facility in Grenoble, scanning the specimen at beamline ID19 with 30 keV X-rays, 2,500 projections over 180 degrees, and a voxel size of just 20.24 micrometres. From those scans, more than 3,600 two-dimensional slices across three spatial planes were assembled into a digital 3D model of the wing.

Why go to such lengths over a wing the size of a grain of rice? Because insect wing venation is one of the most hotly debated subjects in palaeontology. For over two centuries, scientists have argued about how many main veins insect wings contain and how to identify them, and no single system has ever been universally accepted. A recent framework proposes seven main veins in neopteran insects: the costal, subcostal, radial, median, cubital, postcubital and anal veins. Crucially, microtomography gives researchers access to the very base of the wing, where veins emerge from structures called basivenalia, allowing veins to be identified by their origins rather than by superficial appearance. This is what makes a 3D reconstruction so much more powerful than a photograph of an imprint.

The reconstruction revealed that the general structure of the forewing of Picogryllus carentonensis is strikingly similar to that of modern crickets. The wing is divided into a lateral field, running vertically along the body, and a dorsal field, lying flat over the insect’s back, separated by a median fold. The lateral field carries three main veins, Sc, R and M+CuA, with the subcosta pectinate, bearing at least eight oblique branches directed toward the anterior edge. Between the radial and median veins lies the long, narrow lanceolate cell, roughly 4.5 times longer than wide, a hallmark of singing crickets. The dorsal field contains the cubital, postcubital and anal veins, including the harp, a triangular resonating cell, and the mirror, the rounded cell that plays a key role in projecting cricket song.

The researchers identified features that are recognised synapomorphies, shared derived characters, of the Orthoptera: the fusion of the media and cubitus anterior veins, and the fusion of CuA with the first anterior branch of CuPa. The two postcubital veins run near the posterior margin of the wing, forming the so-called chord veins of crickets, and an arculus, a distinctive crossvein structure associated with sound production, is present. The pattern matches almost perfectly the general venation scheme proposed for crickets in 2023, which was built on precise homology criteria rather than guesswork. This validation means the fossil can now be placed on a firm morphological footing alongside its living relatives in the family Oecanthidae.

But the tiny cricket also holds a surprise. Its mirror, the cell central to sound radiation, is crossed by two strong, parallel crossveins, a rare feature in extant crickets. Few living species show more than one crossvein in this cell, although some phalangopsid crickets, such as Paragryllus and Paragryllodes, have up to six concentric crossveins, and winged Phaloriinae typically have two transverse ones. Applying the new venation pattern to the genus Oecanthus shows that what looked like two crossveins in that group is actually a single crossvein plus a highly modified c1 cell, making the two-crossvein mirror of Picogryllus genuinely unusual.

Why would a singing cricket need extra crossveins in its mirror? The researchers propose a functional hypothesis: in many contemporary crickets, the mirror is involved in sound propagation, and the crossveins may reinforce the wing membrane against the stresses of vibration. Large, flexible forewings may need such reinforcement to withstand repeated vibration during calling. There is an intriguing size angle as well. In extant crickets, the frequency of the calling song increases as body size decreases, and the smallest living singing crickets are much larger than Picogryllus. The extra crossveins may have allowed the call of this miniature species to remain in relatively low frequencies despite its tiny sound-producing apparatus, effectively stiffening the vibrating surfaces in a way that shifted its acoustic output.

The fossil’s affinities add another layer to the story. The extinct families Baissogryllidae and Protogryllidae show crossveins in the homologous region, but their cell there is open and not closed by a reinforced s1 crossvein as in true crickets, and they also possess a diagonal crossvein and an ant-mirror cell that Picogryllus lacks. The connections of the crossveins in Picogryllus are identical to those in the living phalangopsid Lerneca fuscipennis, which could support a hypothesis of primary homology, but given that these lineages are not closely related to the Oecanthidae, the crossveins are most probably homoplastic, features that evolved independently in different lineages rather than being inherited from a common ancestor.

Microtomography has its limits at this scale. The stridulatory file, the row of teeth on a wing vein that scrapes against the other wing to produce sound, could not be reconstructed, which prevents any estimate of the frequency of the calling song of Picogryllus. The authors suggest that nanotomography might increase resolution, but caution that the regions in question appear damaged, so finer scanning would probably not recover the missing structures. Even so, this is the first time an almost complete 3D venation pattern has been reconstructed in a fossil Orthoptera, and the technique is proving transformative for studying falsely-flat structures like wings, in both fossil and living taxa.

The implications reach well beyond one tiny cricket. Precise morphological information from fossils is exactly what is needed for modern phylogenetic analyses, including tip dating and total-evidence approaches that combine molecular data from living species with morphological data from extinct ones. Fossils lack DNA, but a validated venation pattern like this one allows accurate placement of extinct species in the tree of life. Two other Cretaceous oecanthid crickets recently described from Myanmar amber, Crassicorpus maculatus and Ordicalcaratus inconditus, are congruent with the new interpretations, though their mirror cells will need closer checking. With this exquisitely preserved 100-million-year-old wing now fully mapped, palaeontologists have a validated morphological basis for reconstructing how cricket wings, and the songs they produce, evolved over hundreds of millions of years.

Subject of Research: Paleontology

Article Title: First 3D reconstruction of a forewing of a fossil Orthoptera : Interpreting the venation pattern in the smallest known cricket with a stridulatory apparatus, † Picogryllus carentonensis ( Orthoptera , Grylloidea , Oecanthidae )

Article References: Ferreira, J., Josse, H., Denadai de Campos, L., Nel, A., & Desutter-Grandcolas, L. (2024). First 3D reconstruction of a forewing of a fossil Orthoptera: Interpreting the venation pattern in the smallest known cricket with a stridulatory apparatus, †Picogryllus carentonensis (Orthoptera, Grylloidea, Oecanthidae). Fossil Record, 27(1), 101-110. https://doi.org/10.3897/fr.27.113100

Image Credits: AI Generated

DOI: 10.3897/fr.27.113100

Keywords: paleontology, crickets, orthoptera, amber fossils, microtomography, evolution, bioacoustics, Cretaceous, First, reconstruction, forewing, fossil

The Yumidong Cave sits at about 1100 meters above sea level in the Miaoyu Basin at the northern foot of the Wushan Mountains, roughly four kilometers from the famous Longgupo Cave, a site central to Quaternary paleontology in China. The cave is a horizontal karst feature developed in limestone, and its stratigraphic sections interbed sandy clay with limestone breccia, recording alternating warm and cool phases that researchers have correlated with marine isotope stages from MIS 8 down to MIS 1. Dating results and faunal comparisons place the fossil-bearing layers in the Mid-Late Pleistocene. Flying squirrels rank among the most abundant groups in the mammalian fauna collected there, giving paleontologists excellent material for detailed morphological comparison of a group that has often suffered from misidentification in earlier studies.

The largest and most abundant species in the assemblage is Pteromys volans, the Siberian flying squirrel, a Palaearctic cold-adapted glider that today ranges from northeast Europe to the Korean Peninsula and Hokkaido. Specimens are plentiful in the cave, making up 9 percent of small mammalian fossils in layer ②-2 and a striking 46 percent in layer ④. The mandibles are very short, with length close to height, and carry a particularly marked angular process wider than the ascending ramus. The cheek teeth are brachyodont, with P3 small but bearing differentiated cusps, P4 fully molarised, and M3 lacking a metaloph and metaconule. On lower teeth, the mesoconid and entoconid are permanent, the trigonid basin remains open, and m3 is conspicuously elongated. These features distinguish the Yumidong material from other small Pleistocene flying squirrels of south China, such as Hylopetes electilis with its pitted cheek tooth enamel, and from the Early Pleistocene Pteromys huananensis known only from Longgupo Cave.

Trogopterus xanthipes, the complex-toothed flying squirrel endemic to China, is the second species identified. It still survives in the region today, living from temperate subalpine coniferous forest to subtropical broad-leaved forest at altitudes of 1360 to 2750 meters. The Yumidong mandibles are high and strong, with a deep pterygoid muscle fossa and a vascular notch that is extensive. The upper cheek teeth carry a well-developed mesostyle connecting paracone and metacone, an enlarged metaconule, and numerous cristae dividing the anterior and posterior valleys into several enamel loops. Lower molars develop metalophids and folds in the talonid basin, making the occlusal surface more complex than that of p4. The genus is diagnosed by this complex dentition and by size: Trogopterus is significantly larger than its closest relative Belomys, with almost no overlap in cheek tooth measurements.

Belomys pearsonii, the hairy-footed flying squirrel, is the third species. It is widely distributed today in south China, northeastern South Asia and Southeast Asia, but has completely disappeared from the Wushan area, although subfossils were reported from the Neolithic Dahekou site in Chongqing. The mandible and teeth closely resemble Trogopterus xanthipes, but the species is much smaller and more lower-crowned. Several dental differences separate the two: P3 of Belomys sits closer to the protocone of P4; the protocone of P4-M2 is more developed while the hypocone is weaker; and the hypocone and metaloph of M3 are absent, whereas in Trogopterus the hypocone is permanent and connects with the metaconule by a straight metaloph. Within the genus, the Early Pleistocene Belomys parapearsoni is smaller with a lower crown, and the Thai Late Pleistocene Belomys thamkaewi falls within the size range of Chinese fossil B. pearsonii, so the Yumidong material is confidently assigned to B. pearsonii.

The fourth species, Aeretes melanopterus, is the largest flying squirrel in the assemblage and one of the rarest mammals in China today, confined to the northeastern Qinghai-Tibet Plateau, the Hengduan Mountains, the Qinling Mountains and a small population near Beijing. It inhabits coniferous and broad-leaved mixed forest at 2500 to 3000 meters and nests on high trees. The Yumidong mandible is robust with a short diastemal portion, and the cheek teeth are subhypsodont with slightly rugose enamel, the lingual wall of upper teeth higher than the buccal wall. P4 is molariformed and triangular in outline, with a small protocone separated from the developed hypocone by a vertical anterolingual flexus extending to the crown base. The genus differs from Petaurista, whose M1/2 lacks a hypocone, and the Yumidong specimens fall within the size and morphological variation of the living species, though they are smaller than Pleistocene specimens from the Tianyuan Cave in Beijing.

Reading these four species together as environmental indicators produces a clear paleoecological signal. All four can adapt to coniferous and broad-leaved mixed forest and alpine coniferous forest, but Pteromys volans and Aeretes melanopterus are cold-adapted Palaearctic species that have completely vanished from the study area and its vicinity. Both were excavated mainly from layer ②-2 and layer ④, the cool phases correlated with MIS 2 and MIS 4, and neither appears in layers ③ and ⑤, the warm phases of MIS 3 and MIS 5. The conclusion is that during MIS 2 and MIS 4 the area around Yumidong Cave was dominated by subalpine evergreen coniferous forest or coniferous and broad-leaved mixed forest, colder and richer in conifers than today, resembling the vegetation now found on Wushan peaks above 2000 meters. During MIS 3 and MIS 5 the landscape was similar to the present subtropical environment.

The regional extinction of the cold-adapted species follows a pattern the authors trace through the glacial-interglacial cycle. Cold-adapted flying squirrels spread southwards during glacial periods and disappeared from the area during interglacials. They likely occupied the middle zone of the Wushan Mountains during the latest Pleistocene or the Last Glacial Maximum, but when the Holocene Megathermal arrived, their habitats contracted to higher peaks. Those limited ecological spaces could not sustain viable populations, and the squirrels died out regionally. Nearby caves reinforce the picture of vertical zonation controlling faunal divergence: Baotansi Cave at about 820 meters shares the same species combination, while Migong Cave at only 160 to 200 meters records a cool but sparser forest with no flying squirrel fossils at all, showing that altitude differences within the same period produced different habitats across the Three Gorges area.

The study also corrects earlier records that seemed to show cold-adapted flying squirrels surviving into the Holocene. Re-examination of material from the Dahekou Neolithic site in Fuling District shows that specimens originally identified as Trogopterus xanthipes should be Belomys pearsonii, that the records of Petaurista petaurista and Aeretes melanopterus appear to be an undetermined Petaurista species, and that the material called Hylopetes alboniger actually belongs to the subfamily Sciurinae and resembles Tamiops swinhoei. Current evidence therefore cannot demonstrate that Pteromys volans, Trogopterus xanthipes or Aeretes melanopterus persisted from the Last Glacial through the Holocene in the Three Gorges area, sharpening the extinction timeline for the cold-adapted fauna.

With four species of four genera identified from abundant maxillae, mandibles and isolated teeth, Yumidong Cave now stands as one of the richest flying squirrel localities of the Chinese Quaternary, and the detailed morphological descriptions set a new standard for a group long neglected in Pleistocene faunal lists. The assemblage demonstrates how a single cave sequence can track the interplay between climate oscillation, vertical mountain zonation and regional extinction. As ice ages deepened, coniferous forest climbed down the slopes and cold-adapted gliders followed; as warmth returned, the forest retreated upward and the squirrels with it, until the Holocene Megathermal pushed their refugia beyond the limits of survival. The fossil teeth of Yumidong thus preserve not just species but the rhythm of forests rising and falling across the mountains of the Three Gorges.

Subject of Research: Pleistocene flying squirrel fossils from Yumidong Cave, China

Article Title: Fossil flying squirrels ( Petauristinae , Sciuridae , Rodentia ) from the Yumidong Cave in Wushan County, Chongqing, China

Article References: Pang, L.-B., Chen, S.-K., Hu, X., Wu, Y., & Wei, G.-B. (2024). Fossil flying squirrels (Petauristinae, Sciuridae, Rodentia) from the Yumidong Cave in Wushan County, Chongqing, China. Fossil Record, 27(1), 209-219. https://doi.org/10.3897/fr.27.115693

Image Credits: AI Generated

DOI: 10.3897/fr.27.115693

Keywords: flying squirrels, Yumidong Cave, Pleistocene, paleoenvironment, China, Fossil Record, extinction, Petauristinae, Fossil, flying, squirrels, Sciuridae

The roots of the museum reach back to the founding of the Universität zu Berlin in 1810, whose collections in mineralogy, zoology and palaeontology formed the seed of what would become one of the world’s great natural history institutions. Geosciences were represented from the start by the mineralogist Christian Samuel Weiss. In 1889 the collections moved from the university’s main building at Unter den Linden 6 to Invalidenstrasse 43, the museum’s address to this day. Only three departments were installed in the new building: Mineralogy, Geology and Palaeontology, and Zoology. For the next four decades palaeontology dominated the geosciences there, until the arrival of the tectonic geologist Hans Stille shifted the emphasis toward geology in the broader sense.

The Department of Geology survived the Second World War, but it did not survive the university reform of the German Democratic Republic in 1968, when it lost its independence as a department. The curatorships continued to exist within the Humboldt Universität, the postwar name of the Friedrich-Wilhelm-Universität. After German reunification in 1990, three scientific departments were reestablished at the museum: Palaeontology, Mineralogy and Zoology. Palaeontology was reconstituted as Palaeobiology, and, uniquely for Germany, given teaching duties in the Department of Biology of the Humboldt Universität. The reasoning was pragmatic: classical geology and palaeontology already existed at the Freie Universität in Berlin, and applied geology at the Technische Universität, so the museum’s palaeontologists would anchor their discipline in biology instead.

All three departments belonged to the Humboldt Universität, with one of the three directors serving as general director of the museum. The mineralogist Dieter Stöffler held that rotating role in the first years from 1993 to 1999, followed by the palaeontologist Hans-Peter Schultze from 1999 to 2004. The museum’s budget had to be negotiated among the three directors, and one recurring item concerned publications. The Department of Zoology published three scientific journals: the Mitteilungen aus der Zoologischen Sammlung des Museums für Naturkunde in Berlin since 1898, the Deutsche Entomologische Zeitschrift since 1857, and the Annalen für Ornithologie since 1977. The other two departments published nothing of their own.

The Department of Palaeontology had a strong interest in changing that deficiency. Its researchers wanted a venue for monographs and thematic volumes, such as one dedicated to the famous Tendaguru dinosaur locality in Tanzania, whose fossils had been collected before the First World War. The Department of Mineralogy, by contrast, preferred not to publish in an in-house journal. The director of Zoology, Ulrich Zeller, was willing to integrate the Annalen für Ornithologie with the Mitteilungen aus der Zoologischen Sammlung, and as a consequence basic funding became available for a geoscience journal. The palaeontologists seized the opportunity.

During the discussions over a name for the new geoscience journal, director Stöffler argued for a corporate appearance: all three journals of the museum would share the common title Mitteilungen aus dem Museum für Naturkunde in Berlin, meaning Communications from the Museum of Natural History in Berlin, distinguished only by subtitles. The palaeontological journal became the Geowissenschaftliche Reihe, the zoological journal the Zoologische Reihe, and the entomological journal retained the name Deutsche Entomologische Zeitschrift. In 1998 the first volume appeared, and the museum’s palaeontologists finally had a journal of their own.

From the beginning, the editors pursued an internationalization strategy with two technical pillars: opening the journal to authors outside the museum and publishing mainly in English. Managing editor Gloria Arratia worked hard toward that goal, approaching and inviting colleagues beyond the museum’s walls and explaining the advantages of publishing there. The numbers show the strategy worked: a little more than half of the authors in the early years were not members of the Palaeontology Department. On the other side, assistant editor Petra Keßling helped old colleagues from the GDR adapt to modern publication requirements, apart from continuing to publish in German. From volume 1 in 1998 until volume 8 in 2005, 97 papers appeared under the Mitteilungen banner. Volume 2 contained 14 papers on fossils from Tendaguru, and volume 5 was a Festband celebrating the 65th birthday of department director Hans-Peter Schultze with 21 papers.

The decisive technical modernization came with volume 8 in 2005, when the new managing editor Dieter Korn prepared the journal for acceptance in the citation index, with articles assigned a digital object identifier and made available online. With volume 9 in 2006, the journal appeared in two issues per year under a new title: Fossil Record, a name suggested by palaeontologist Wolfgang Kiessling. Starting with volume 11 in 2008, the journal adopted a new color and a changing design from issue to issue. The zoological journal received a parallel rebranding as Zoosystematics and Evolution. The corporate umbrella title was finally dropped when the journals moved to the new publisher Pensoft, in 2014 for the Deutsche Entomologische Zeitschrift and Zoosystematics and Evolution, and in 2021 for Fossil Record itself.

The trajectory of Fossil Record reflects broader shifts in scientific publishing over the past quarter century. What began as a museum house organ, constrained by a German-language corporate identity and a largely local readership, deliberately retooled itself for the international citation economy: English as the primary language, DOIs for every article, indexed issues, and a flexible visual design that signaled modernity. The result, as the new account documents, is a journal that has developed from an in-house publication with international contributions into an internationally well cited journal. For palaeontologists, the story is a reminder that the fossil record of science itself, the paper trail of institutions, budgets and journal titles, can be as revealing as any specimen locked in stone.

Subject of Research: History of science

Article Title: The start of the scientific journal ‘Fossil Record’

Article References: Schultze, H.-P. (2024). The start of the scientific journal ‘Fossil Record’. Fossil Record, 27(3), 295-297. https://doi.org/10.3897/fr.27.141907

Image Credits: AI Generated

DOI: 10.3897/fr.27.141907

Keywords: start, scientific, journal, Fossil, Record, scientific research

The research, led by palaeontologist Rainer Schoch of the State Museum of Natural History Stuttgart, draws on nearly 200 years of collections from nine localities across Baden-Württemberg and Thuringia. The material ranges from the historically famous alum mine at Gaildorf, which yielded the first temnospondyl remains ever described in 1828, to the spectacular fossil-rich layers excavated at Kupferzell and Vellberg-Eschenau in recent decades. By analysing skulls, mandibles, vertebrae and girdle elements across every size class, the study reconstructs how this animal grew, what its youngest stages looked like, and which habitats it occupied at different points in its life.

The smallest specimens in the sample are astonishingly tiny. Two symphyses, the fused chin regions of lower jaws, recovered from screen-washed sediment at Kupferzell measure just one and two millimetres in length. They belong to individuals with estimated skull lengths of only 12 to 15 millimetres, ranking among the smallest stereospondyl specimens ever identified anywhere in the world. Even at this larval scale, the diagnostic features of Mastodonsaurus were already in place: the enlarged symphyseal fangs and the characteristic arrangement of teeth distinguish these fragments unambiguously from the juveniles of other temnospondyls sharing the same lakes, such as Tatrasuchus, Callistomordax and Trematolestes.

What emerges most strikingly from the analysis is how conservative the animal’s body plan remained throughout its life. Cranial proportions changed remarkably little from juvenile to giant stages. The orbits, the large eye openings that reached one-fifth of skull length, decreased only very moderately in relative size as the animal grew. The postorbital portion of the skull became slightly longer and the occipital margin at the back of the head grew more deeply concave in the largest individuals, but these are subtle shifts for an animal that increased its skull length a hundredfold. Small juveniles already carried the same coarse dermal ornament on their skull bones as the adults, and the heavy, disc-shaped intercentra that formed the vertebral centres were established early in the juvenile phase.

Some changes were nonetheless significant. The largest specimens developed disproportionately large symphyseal fangs at the front of the lower jaw, and their neural arches bore transverse processes that grew with strong positive allometry. In the giant skulls, the ornament on the bone surface became coarser, with larger polygons and relatively thinner ridges than in mid-sized animals. The choana, the internal nostril opening in the palate, was distinctly smaller in the biggest Gaildorf specimen than in smaller adults. These shifts likely reflect changing biomechanics as the animal moved from hunting small prey to tackling increasingly large targets.

The study also mapped the frequency and size distribution of Mastodonsaurus across six different lake deposits in the Lower Keuper of southern Germany, and the results reveal a sophisticated pattern of habitat use across the life cycle. The coal-bearing deposit at Gaildorf stands out: it yielded unusually large specimens, including complete skulls of 60 to 68 centimetres and the lost remains of a giant with an estimated 107-centimetre skull, together with relatively well-ossified limb skeletons. The researchers suggest that the Gaildorf population may have lived longer or grown faster under favourable conditions, and that the presence of the smaller capitosaur Tatrasuchus may have driven character displacement, pushing Mastodonsaurus toward even larger sizes as the apex predator of that lake.

At Kupferzell, the richest tetrapod fossil site in the Lower Keuper, the size distribution of Mastodonsaurus is strikingly bimodal, clustering in the 18 to 32 centimetre and 40 to 65 centimetre skull-length ranges, with tiny larvae identified in screen-washed samples and a single giant specimen of 88.5 centimetres. This lake, interpreted as a shallow, well-aerated water body less than ten metres deep, evidently served as a nursery and growth habitat. By contrast, the lake shore facies at Kupferzell K4 and Vellberg E7 contain only adult specimens, suggesting that juveniles avoided these more exposed environments and dwelled in calmer waters instead.

The Vellberg deposits tell an equally nuanced story. The small lake E5, dominated by the competing predator Tatrasuchus, hosted only occasional adult Mastodonsaurus in a narrow 50 to 60 centimetre range, apparently unable to sustain a full population. The larger, deeper lake E6, however, preserved specimens of every size class, from larvae to giants approaching 120 centimetres in skull length. E6 also provides the only evidence so far of cannibalism in Mastodonsaurus, including a 60-centimetre skull bearing bite marks from a much larger conspecific. Regurgitated bones and corroded lungfish teeth scattered through the deposit confirm that this lake was a hunting ground where the giant ambushed fish, smaller temnospondyls and even the amphibious archosauriform Jaxtasuchus.

Prey was never in short supply. The diverse actinopterygian fish fauna of these lakes ranged from three-centimetre Dipteronotus to 30-centimetre scanilepiforms, providing food for every growth stage of the giant predator. At Gaildorf, the most likely prey was the large bottom-dwelling Plagiosuchus; at Kupferzell, the smaller Gerrothorax, lungfishes and coelacanths; at Vellberg, Plagiosuchus and Tatrasuchus, as evidenced by heavy bite marks on their skulls. Yet the giant itself was not invulnerable: the pseudosuchian archosaur Batrachotomus kupferzellensis scavenged and possibly hunted Mastodonsaurus carcasses, leaving abundant bite marks on bones at both Kupferzell and Vellberg.

The new growth series demonstrates that Mastodonsaurus giganteus was not only the largest temnospondyl known but also one of the most ecologically flexible. It bred and grew in large, resource-rich lakes, visited smaller water bodies only as adults, and partitioned niches with competing predators where conditions allowed. Its presence, the study concludes, was apparently governed less by the stability of living conditions than by the question of which capitosaur reached a lake first. In an age when the ancestors of dinosaurs were still small and inconspicuous, the giants of the Triassic waterways were amphibians, and Mastodonsaurus ruled them all.

Subject of Research: Ontogeny and life history of the giant Triassic temnospondyl Mastodonsaurus giganteus

Article Title: Growing giants: ontogeny and life history of the temnospondyl Mastodonsaurus giganteus ( Stereospondyli ) from the Middle Triassic of Germany

Article References: Schoch, R. R., Witzmann, F., Moreno, R., Werneburg, R., & Mujal, E. (2024). Growing giants: ontogeny and life history of the temnospondyl Mastodonsaurus giganteus (Stereospondyli) from the Middle Triassic of Germany. Fossil Record, 27(3), 401-422. https://doi.org/10.3897/fr.27.125379

Image Credits: AI Generated

DOI: 10.3897/fr.27.125379

Keywords: Mastodonsaurus giganteus, temnospondyl, Triassic, ontogeny, palaeoecology, Germany, Lower Keuper, fossil, amphibian, stereospondyl, Kupferzell, Vellberg

Jradzor sits within the Gegham volcanic province of the Lesser Caucasus, a landscape shaped by eruptions, ash flows, and volcanic lakes. The diatomite deposits there were first discovered in the 1960s and have been actively mined since the 2000s. Paleontological investigations, directed by Dr. Davit Vasilyan, began during the active phase of mining and recovered a rich assemblage of fishes, reptiles, birds, and mammals. What makes the site exceptional is its dating: the stratigraphic section has been pinned down through a combination of argon-40/argon-39 radiometric analyses, magnetostratigraphy, and biochronological correlations, giving researchers an unusually precise temporal framework for the fossils.

The sedimentary succession records a complex depositional history. A short-lived dammed lake formed around 4.3 million years ago and was subsequently overwhelmed by pyroclastic density flows between roughly 4.3 and 3.93 million years ago. Paleosols then developed between 3.9 and 3.1 million years ago. The ruminant remains analyzed in the study originate from four fossiliferous horizons. Three of them, labeled JZ-2a, JZ-11, and JZ-3s, date to between 4.16 and 3.98 million years ago and represent pyroclastic flows rich in small vertebrate fossils but containing relatively few large-mammal remains. The fourth horizon, JZ-7, dated to 3.3 plus or minus 0.03 million years ago, corresponds to a catastrophic lahar, a violent volcanic mudflow, that buried an abundant large-vertebrate fauna alongside a limited number of small-vertebrate fossils.

Large-mammal faunas from this interval are poorly documented across Southwest Asia. The only other locality that has yielded a comparable assemblage is Çalta in Turkey, dated to about four million years ago. Within this context, Jradzor constitutes a regionally important site that provides new insights into the Pliocene faunal diversity of this geographic crossroad. The available specimens are few in number and not sufficiently diagnostic for higher-resolution taxonomic identification, and further discoveries are unlikely because the fossiliferous deposits at the site have been fully exhausted. The material described in the paper therefore represents the entire taxonomically significant ruminant record currently available from Jradzor.

From the lower horizons, dated to the end of the Early Pliocene, the researchers identified four lineages from just four isolated teeth. One tooth, an incomplete upper molar with distinctly wrinkled enamel, points to a very large cervid, a deer belonging to the subfamily Cervinae. The size of the specimen indicates the presence of a very large deer at Jradzor around four million years ago, comparable to the largest specimens of the Early Villafranchian genus Arvernoceros from Europe and to Rucervus simplicidens from the Early Pliocene of the Siwaliks. The buccal walls of the tooth lobes are not obliquely oriented to the longitudinal axis, a feature that excludes large members of the subfamily Capreolinae and supports attribution to Cervinae. Identification based on a single tooth is inherently problematic, but the researchers note that the specimen, together with the deer from Çalta, may represent one of the earliest large-sized cervines in the Palearctic realm.

A second tooth from the lower horizons, an unerupted deciduous upper fourth premolar lacking roots and crown wear, belonged to a bovine calf only a few weeks old. The enamel pattern and overall morphology are characteristic of the tribe Bovini, the group that includes cattle and their relatives. Remarkably, the relatively complex occlusal relief and stronger, localized paracone fold distinguish the Jradzor specimen from the European Pliocene genera Parabos, Alephis, and Grevenobos, suggesting a more derived morphology. This condition is comparable to that of Leptobos, although it does not necessarily imply affiliation with the clade comprising bison, aurochs, and their allies. The Jradzor fossil postdates, or closely coincides with, molecular estimates for the divergence of the bison-aurochs clade, which occurred between roughly 5.0 and 3.3 million years ago, whereas the buffalo clade had already differentiated by the Late Miocene. From a biogeographic point of view, this bovine represents a lineage of Oriental origin, and its occurrence predates the earliest known derived bovines in the Palaearctic zone by roughly one million years.

The remaining two teeth from the lower horizons belong to antelopes. An isolated lower third molar with notably thick enamel, a pronounced goat fold, and a smooth undulating lingual surface may belong to a different, smaller antelope than the spiral-horned Gazellospira found higher in the sequence. Although its small size could suggest attribution to the genus Gazella, the thicker enamel and the well-developed goat fold seem more consistent with the Eurasian spiral-horned antelopes, though this interpretation remains tentative. A deciduous upper fourth premolar with smooth enamel, a central fossetta, and a robust mesostyle points to a large representative of the subfamily Caprinae, possibly with affinities to the musk ox or goat-antelope tribes.

The upper horizon, dated to 3.3 million years ago and corresponding to the beginning of the early Villafranchian, yielded three lineages. Gazellospira, a medium-size spiral-horned antelope, is the most abundant ruminant at Jradzor, represented by maxillae, mandible fragments, and complete metapodials. The size, proportions, and detailed morphology of the Jradzor antelope are fully consistent with Gazellospira torticornis, though a definitive species-level attribution is not justified owing to the absence of cranial material and the challenged taxonomy of medium-size spiral-horned antelopes. The two complete metapodials fall within the lower size range of the Villarroya assemblage in Spain and are longer than those of younger Gazellospira populations from southern Europe, reflecting a reported temporal and latitudinal trend in metapodial size variation across Europe. The Jradzor occurrence constitutes one of the earliest confidently dated records of the genus and documents a widespread radiation of this antelope lineage throughout Western Temperate Eurasia, from the Caucasus to the Iberian Peninsula.

A complete right metacarpal from the upper horizon exhibits typical caprine morphology and shows striking similarity, in both morphology and size, to a specimen belonging to Eosyncerus ivericus from the Early Villafranchian Kvabebi fauna in Georgia. Eosyncerus is a problematic taxon, initially assigned to Bovinae, but cranial, dental, and postcranial morphology indicate that it more appropriately belongs to Caprinae. Based on this morphological resemblance and the close geographic proximity, despite a temporal gap of approximately 600,000 years between Kvabebi and Jradzor, the specimen is referred to Caprinae indeterminate, cf. Eosyncerus. A smaller distal metacarpal fragment from the same horizon, with a deep and wide intertrochlear incision, abrupt distal widening, and triangular outline of the trochlear external margins, suggests the presence of a goat-like bovid at Jradzor and represents some of the earliest evidence of the Caprini clade in Southwest Asia.

Overall, the Jradzor site provides evidence for the earliest Western Palearctic occurrences of several lineages of Central and East Asian origin, including the Caprini and the cf. Eosyncerus from the upper assemblage, and of Oriental origin, including the Bovini and possibly the large Cervinae from the lower assemblage. The fauna documents crucial evidence for Pliocene faunal exchanges between the Oriental, Eastern, and Western Palearctic regions and underscores the biogeographic significance of the South Caucasus as a major migration corridor during the Pliocene. Despite the limited number of specimens, the exceptionally well-dated and carefully collected fossil material from Jradzor, combined with the general scarcity of Pliocene mammal faunas in Southwest Asia, makes the site an important reference point for understanding the palaeobiogeographic and biostratigraphic patterns of Eurasian ruminants. As the researchers acknowledge, the scarcity of the material raises more questions than it provides answers, but the Jradzor record now stands as a crucial anchor for reconstructing the assembly of Eurasian mammal communities at a time when the continent’s faunal geography was being redrawn.

Subject of Research: Fossil ruminants from the Pliocene site of Jradzor, Armenia

Article Title: Fossil ruminants from the Pliocene site of Jradzor, Armenia

Article References: Bukhsianidze, M. (2026). Fossil ruminants from the Pliocene site of Jradzor, Armenia. Swiss Journal of Palaeontology, 145, 199-211. https://doi.org/10.3897/sjp.145.177453

Image Credits: AI Generated

DOI: 10.3897/sjp.145.177453

Keywords: Fossil, ruminants, Pliocene, site, Jradzor, Armenia, scientific research

The revision, led by researchers examining dozens of newly recovered teeth from Upper Jurassic marine deposits near the village of Mahlstetten in southwestern Germany, demonstrates that this animal was not a synechodontiform at all. Instead, the evidence points to it being a galeomorph, the superorder that contains most familiar modern sharks, including hammerheads, tiger sharks and catsharks. The finding reshapes how palaeontologists view the diversity of Jurassic shark faunas and highlights just how much evolutionary experimentation was underway in the seas of that era.

Elasmobranchs, the group that includes sharks, rays and skates, are among the most successful lineages of cartilaginous fishes. They first appeared at the end of the Palaeozoic and underwent a major diversification during the Jurassic, when nearly all of their major clades show up in the fossil record. Yet reconstructing that history is notoriously difficult. Because shark skeletons are made of cartilage, they rarely fossilise intact. The overwhelming majority of what palaeontologists know about ancient sharks comes from isolated teeth and dermal denticles, the tiny tooth-like scales that covered their skin.

Teeth are abundant because sharks are polyphyodont, meaning they continuously shed and replace their teeth throughout their lives. This constant turnover produces enormous quantities of dental remains, which are highly valuable for taxonomy. But it also creates problems. Shark dentitions are heterodont, meaning that teeth vary considerably in shape depending on their position along the jaw, with differences running from the front of the mouth to the back and sometimes between upper and lower jaws. Distinguishing between features that are genuinely diagnostic of a species and those that simply reflect where a tooth sat in the mouth requires careful analysis, and many fossil species described in past centuries were based on material far too incomplete to capture this variation.

The genus Synechodus itself illustrates the problem. Its type species, Synechodus dubrisiensis, was described from an associated tooth set found in Late Cretaceous deposits in England. Over twenty additional species were subsequently assigned to the genus, spanning an extraordinary range from the Permian to the Palaeocene. But researchers have increasingly noticed that many of these species differ from the type in significant ways, including crown ornamentation and the pattern of vascularisation inside the roots. The Permian species Synechodus antiquus and several Triassic forms already show clear differences, and it is likely that many of them belong to genera that have yet to be identified. Synechodus, in other words, may be functioning as a waste-basket taxon, a convenient label for anything that looks vaguely similar but resists precise classification.

Curvorudentis prorogatus was caught in exactly this trap. Kriwet described it in 2003 from Callovian deposits at Kłęby in northwestern Poland, assigning it to Synechodus primarily on the basis of root characters such as short root grooves and several margino-lingual foramina. When four additional teeth were later discovered at Ogrodzieniec Quarry in southern Poland, from Middle Callovian and lower Oxfordian layers, questions began to mount. Those teeth showed significant differences from Synechodus dubrisiensis, particularly in root structure and crown ornamentation, casting doubt on the original assignment.

The new material from Mahlstetten changes the picture entirely. The fossiliferous layers there are greyish marls of the Mutabilis zone, dating to the early Kimmeridgian stage of the Late Jurassic, deposited under outer-shelf and open-water conditions. This contrasts with the restricted environments of the contemporaneous Solnhofen Archipelago and Nusplingen Lagerstätten. A private collector, E. Unger of Ravensburg, spent many years recovering palaeontological material from the site, and the specimens used in the study were subsequently donated to the State Museum of Natural History Stuttgart. Researchers photographed the teeth using scanning electron microscopy after sputter-coating them at the Museum of Natural History in Berlin, allowing extremely detailed examination of their surface features.

What those images revealed is a dental architecture unlike anything else in the Jurassic. The teeth are wide, with up to three pairs of lateral cusplets flanking a triangular main cusp. The basal labial margin, the front edge of the tooth near its base, is distinctly sinuous and curves into a pronounced concave arch beneath the main cusp. The labial crown face carries folds that run parallel to the cutting edges, with additional short vertical ridges on the cusps and cusplets, and a prominent labial crown extension that covers the root. Inside the root, the vascularisation follows a hemiaulacorhize pattern, with foramina and parallel nutritive grooves opening onto the lingual protuberance. None of these features match Synechodus, whose teeth lack the basal labial curvature and the parallel labial folds, and whose roots show a pseudopolyaulacorhize vascularisation pattern with a basally flat root and a typical labial depression.

The comparison with other Jurassic sharks was equally revealing. Teeth of Paraorthacodus, another synechodontiform genus, have a straight labial margin ornamented with sub-vertical ridges and delicate, well-separated cusplets, quite unlike the curved, fold-bearing teeth of Curvorudentis. The monotypic genus Bavariscyllium, from the Tithonian of the Solnhofen Archipelago, has shorter anterior teeth with lower, more acute cusplets and asymmetric root lobes. Palaeocarcharias, traditionally considered an early lamniform, has mesiodistally compressed teeth with no ornamentation and no lateral cusplets at all. Palaeoscyllium, another Solnhofen genus, shows strongly marked apico-basally directed ridges and a compressed lingual protuberance. Curvorudentis stands apart from all of them, and the researchers concluded that it required not just a new species assignment but a new genus, named from the Latin words for curvatures and tooth, in reference to the distinctive curved basal labial margin.

The reassignment to galeomorphs rests on several characters of high taxonomic value: the centrally developed concavity of the basal labial crown face, the well-developed crown shoulders, the presence of numerous open foramina in the lingual face of the root, and the hemiaulacorhize vascularisation pattern with divergent and basally oriented root branches. These traits are widely observed in both modern galeomorphs, such as the catshark Halaelurus bürgeri and the proscylliid Proscyllium habereri, and in fossil galeomorphs like Palaeoscyllium and Bavariscyllium. Interestingly, the teeth also show what appears to be a minor dignathic heterodonty, the kind of difference between upper and lower jaw teeth seen in living galeomorph sharks, where upper jaw teeth have cusps inclined toward the commissure while lower jaw teeth stand upright. More material will be needed to confirm this, but the pattern is suggestive.

Where exactly Curvorudentis sits within the galeomorphs remains unresolved. The researchers note that it shares some features with modern carcharhiniform taxa but differs in others, including the lateral extension of the enameloid, the labial crown folds parallel to the cutting edges, and the almost squared, mesiodistally elongated root with oblique and divergent branches. The systematic positions of Palaeoscyllium and Bavariscyllium within galeomorphs have also recently been challenged and remain uncertain, and Curvorudentis appears to be in a similar position, a galeomorph whose precise affinities cannot yet be pinned down.

The Mahlstetten discovery also extends the geographic and temporal range of the species considerably. Previously known only from Middle Jurassic deposits in Poland, Curvorudentis prorogatus is now documented from the early Kimmeridgian of Germany, its stratigraphically youngest occurrence to date. Its environmental distribution spans from nearshore settings in Poland to the offshore conditions of Mahlstetten, suggesting that this was a small, unspecialised mesopredator, comfortable in a range of marine habitats. As palaeontologists continue to re-examine old collections with modern imaging techniques and larger comparative datasets, it seems likely that more waste-basket taxa will be unpacked, and more unexpected branches of the shark family tree will come into focus.

Subject of Research: Taxonomic revision of a Jurassic shark species based on fossil teeth

Article Title: Revision of the extinct shark Synechodus prorogatus Kriwet, 2003 ( Chondrichthyes , Elasmobranchii ) and its galeomorph affiliation

Article References: Begat, A., Villalobos-Segura, E., Amadori, M., Klug, S., & Kriwet, J. (2026). Revision of the extinct shark Synechodus prorogatus Kriwet, 2003 (Chondrichthyes, Elasmobranchii) and its galeomorph affiliation. Swiss Journal of Palaeontology, 145, 303-311. https://doi.org/10.3897/sjp.145.187852

Image Credits: AI Generated

DOI: 10.3897/sjp.145.187852

Keywords: Jurassic, sharks, paleontology, elasmobranchs, teeth, taxonomy, galeomorphs, Synechodus, Germany, Poland, fossil, heterodonty

Amber is an unusual and precious medium for fossilization. Unlike rock fossils, which are often flattened, distorted, or fragmentary, amber inclusions are preserved in three dimensions with astonishing fidelity, sometimes down to the level of individual cell walls. That makes them uniquely valuable for comparing extinct organisms with living ones. Both Dominican amber, dated to roughly 15 to 20 million years old, and Mexican amber, dated to 15 to 23 million years old, were produced by trees of the genus Hymenaea, a member of the bean family that still grows in Mexico, Central America, and the Caribbean. The resin trapped not only insects but also the delicate epiphytes, organisms that grow on other plants without parasitizing them, that covered the bark and leaves of the ancient forest.

Leafy liverworts of the subclass Jungermanniidae are among the earliest diverging lineages of land plants, yet their fossil record is otherwise scarce because their soft tissues decay quickly. In amber, however, they are remarkably frequent. The order Porellales, in particular, contains many epiphytes and epiphylls, plants that grow on living leaves, and its members show morphological adaptations to life in the canopy. Species-rich families such as Lejeuneaceae, with more than 1,000 extant species, and Frullaniaceae, with more than 675 accepted taxa, are common amber inclusions from the mid-Cretaceous onward. Dominican amber has preserved the best-studied and most diverse Neogene liverwort flora known, and Mexican amber is emerging as a second, still understudied source of well-preserved material.

The first new species, named Frullania chiapasensis after the Chiapas amber deposit, is a small liverwort preserved as two gametophyte fragments, the largest an intact shoot about 2.64 millimeters long. Its leaves are conduplicate-trilobed, folded into three lobes, with a saccate ventral lobule of the classic Frullania type and a sickle-shaped mouth opening along the abaxial side of the lobe. The underleaves are triangular to obovate and armed with short teeth in their upper third. It is only the fourth representative of this hyperdiverse genus, which contains 675 currently accepted taxa and more than 2,000 published names, to be described from New World amber deposits. To establish that the fossil truly represents a distinct species, the team built a morphology matrix comparing it with 144 extant and extinct species across 16 critical characters, including lobule orientation, underleaf shape, and the structure of the lobule mouth.

The closest living relative by these criteria is Frullania simmondsii, which matches the fossil in all 11 additional characters scored. Yet the two can still be separated: the fossil has leaf lobes longer than wide, a foliaceous stylus longer than wide, and underleaves mostly longer than wide with concave lower margins, whereas F. simmondsii shows the opposite states in each case. Eight more extant species differ from the fossil in exactly one character, most often the arrangement of the lobules, which in F. chiapasensis run largely parallel to the stem rather than spreading obliquely. The remaining 135 species in the comparison differ by two to seven characters. The subgeneric assignment of the new species remains problematic because its most similar relatives are currently placed in different subgenera, a reflection of the extensive morphological homoplasy that complicates the taxonomy of this genus even for specialists working with fresh material.

The second new species, Thysananthus patrickmuelleri, named for the amber collector Patrick Müller who provided all known specimens, is a member of the Lejeuneaceae subfamily Ptychanthoideae. Its shoots reach up to 5.04 millimeters in length with leaves, and the species is diagnosed by a ventral merophyte at least five cells wide, flagelliform branches on the lower parts of the shoots, elongate median lobe cells with distinctly cordate trigones, and underleaves with recurved apices and revolute margins. The genus Thysananthus is already rather diverse in Dominican amber, where it includes one extant species and two extinct ones, but this is its first record from Mexican amber. Among living species, the fossil most closely resembles the neotropical T. plicatiflorus of northern South American rainforests, sharing elongate ovate-oblong leaves with rounded apices and auriculate underleaves, but it differs markedly in the squarrose orientation and recurved apex of its underleaves.

A third liverwort specimen, too fragmentary and sterile for species-level description, was assigned to the genus Lejeunea, a cosmopolitan group of about 200 extant species that grows on bark and living leaves in tropical and warm-temperate regions. The fossil shows the obliquely spreading leaf lobes, large flask-shaped lobules with a short straight tooth, and thin-walled leaf cells characteristic of Lejeunea, though its unusually small size, possibly because it represents a branch rather than a main shoot, distinguishes it from most extant members of the genus. Four fossil species of Lejeunea have previously been described from Dominican amber; the Mexican specimen differs from all of them but cannot be ruled out as an extant species given its incomplete preservation.

The lichen fossils are equally significant. Only four lichen species had previously been described from Dominican amber and none at all from Mexican amber, even though lichen-like associations existed as early as 600 million years ago in the Precambrian and stratified thalli are known from 415-million-year-old Devonian strata. The new material includes three specimens from Dominican amber and one from Mexican amber, all belonging to the extant genus Parmotrema, a group of roughly 300 foliose lichens concentrated in tropical and subtropical regions. The fossils show the long, thick, tapered marginal cilia and dark lower surfaces typical of the genus. One Dominican specimen with effigurate maculae on its upper surface resembles the former genus Canomaculina, now synonymized with Parmotrema, while another shows abundant finger-shaped isidia. Because species-level identification of parmelioid lichens relies largely on chemistry invisible in fossils, the specimens were compared at the level of infrageneric groups such as Parmotrema s. str., which contains more than 250 extant species.

These fossils carry real phylogenetic weight. Molecular analyses calibrated with fossils had constrained the age of the parmelioid crown group to around 60 million years and the genus Parmotrema to around 23 million years, but the only fossil calibration previously available within the parmelioid group consisted of two ambiguous specimens tentatively placed in Parmelia that lacked the marginal cilia characteristic of Parmotrema. The newly described Parmotrema fossils, some of which can be assigned to infrageneric clades, now provide a minimum age of 15 to 23 million years for the genus, a substantially firmer calibration point for future dating studies of lichenized fungi.

Taken together, the nine specimens substantiate a hypothesis of generic stasis in neotropical epiphyte communities. Every bryophyte, fern, and lichen genus known from Dominican amber is extant, and Mexican amber appears to have captured a liverwort flora of similar composition, dominated by Porellales and especially Lejeuneaceae. Yet the two deposits also reveal floristic differences: Frullania is represented by three well-delimited species in Mexican amber but only one fragment from Dominican amber, while Spruceanthus extinctus, known only from Mexican amber, belongs to a genus today centered in Asia and Australasia, suggesting that its Miocene distribution was once far wider. Comparable understudied deposits, including early Miocene Shewa amber from Ethiopia, which was also produced by Hymenaea, and mid-Miocene Zhangpu amber from China, promise to further illuminate how these cryptogamic communities evolved as angiosperm-dominated megathermal forests rose to prominence during the Cenozoic.

Subject of Research: Paleontology

Article Title: Extending the fossil record of Miocene neotropical epiphyte communities

Article References: Feldberg, K., Kaasalainen, U., Mamontov, Y. S., Gradstein, S. R., Schäfer-Verwimp, A., Divakar, P. K., & Schmidt, A. R. (2025). Extending the fossil record of Miocene neotropical epiphyte communities. Fossil Record, 28(1), 79-102. https://doi.org/10.3897/fr.28.137758

Image Credits: AI Generated

DOI: 10.3897/fr.28.137758

Keywords: Extending, fossil, record, Miocene, neotropical, epiphyte, communities, scientific research

Baetidae are among the most successful mayfly families on the planet. They occur on nearly every significant landmass except Antarctica, New Zealand, and some oceanic islands, and they reach their greatest diversity and highest levels of generic endemism in tropical regions. Their larvae inhabit freshwater streams and lakes, where they play significant ecological roles as grazers and prey items. Yet despite this modern ubiquity, the family’s fossil record is extremely scarce. The oldest fossil attributed to Baetidae, referred to as Baetidae sp. 1, comes from Early Cretaceous Lebanese amber dated to approximately 129.4 to 125 million years ago, but its preservation is too poor to allow a detailed description. Additional Mesozoic records include Vetuformosa buckleyi from mid-Cretaceous Burmese amber, Palaeocloeon taimyricum from Late Cretaceous Taimyr amber in Northern Asia, and Myanmarella rossi, originally assigned to Prosopistomatidae and later transferred to Baetidae.

The new North Carolina specimen, catalogued as AMNH NC-VK261 in the American Museum of Natural History, was collected by V. E. Krynicki near the Neuse River Cut Off in Wayne County. According to earlier palynological dating by Mitra and Mickle, the type locality represents an outcrop of the Tar Heel Formation dated as early Campanian, approximately 83 million years ago. The amber itself has been embedded in a high-end glass conservation epoxy for protection. A second amber piece containing a partially preserved chironomid midge serves as a syninclusion, offering a glimpse of the insect community that shared the Cretaceous forest with the mayfly. Compared with extensively studied deposits such as Burmese amber from Northern Myanmar, the inclusions in North Carolina amber have received very little scientific attention, with only fossil ants and a phantom crane fly previously described from the deposit.

Morphological analysis of the holotype revealed a suite of diagnostic characters. The body measures approximately 1.9 millimeters, and the specimen is identified as female based on compound eyes that are not distinctly enlarged, forelegs that are not elongated, and the absence of male genitalia. The forewing, roughly equal in length to the body at 2 millimeters, displays a pronounced angle on its posterior margin between the veins CuA and CuP, an unusual feature in Baetidae where this portion of the wing margin is rounded in all extant genera. The hind wing is small, approximately 0.3 times the forewing length, with reduced venation and a small acute costal process positioned basally. The first principal longitudinal vein of the hind wing is sigmoidal, while the second is bifurcated, with an intercalary vein between its branches that is also distally bifurcated and followed by another simple intercalary vein. The tarsi are four-segmented with three movable segments and the basal segment fused with the tibia, and a tibio-patellar suture is present on all legs.

Attribution of the specimen to Baetidae rests on several key characters. The forewing MA2 vein is free, not connected with MA1, a condition that separates Baetidae not only from Siphlaenigmatidae but from all other mayfly families, which exhibit the MA vein bifurcated into MA1 and MA2. Single free marginal intercalary veins are present along the posterior margin of the forewing, well-distinguishable in the median sector of the left forewing, and such marginal intercalary veins are typical for Baetidae. The small hind wing with reduced venation and a basally situated costal process, along with the vestigial paracercus at the tip of the abdomen, further support the placement within the family. Characters associated with the broader group Tetramerotarsata, including the absence of the mesonotal suture, the presence of the sublateroscutal suture, and a CuP vein curved backward near its base, are also recognizable in the fossil, although recent molecular reconstructions suggest these similarities between Baetidae and Siphlaenigmatidae may reflect convergent evolution rather than shared ancestry.

The researchers also evaluated the specimen’s relationship to the Cretaceous subfamily Palaeocloeoninae, known from Burmese and Taimyr amber. Several characters argue against such an assignment. In Petracloeon carolinensis, the furcasternal protuberances on the mesothorax are widely separated, more closely resembling the condition in extant Baetidae, whereas Palaeocloeoninae is characterized by contiguous furcasternal protuberances. The tibio-patellar suture on the forelegs is present in the new fossil but absent in Palaeocloeoninae, and the antennal flagellum is much shorter, approximately twice the head length, compared with the very long flagella exceeding three times head length reported in Palaeocloeoninae females. Based on these character states, the authors declined to place the new genus within Palaeocloeoninae, instead suggesting an affinity with the clade Turbanoculata, which encompasses all extant Baetidae taxa.

Within Turbanoculata, the presence of the tibio-patellar suture in all legs points toward the group Anteropatellata. The hind wing venation, with its bifurcated longitudinal veins and intercalary veins, excludes assignment to Cloeonini, whose members have either no hind wings or slender hind wings with only simple, unforked longitudinal veins. The forewing pattern of single rather than double marginal intercalary veins rules out the clade Baetungulata, whose imagos universally display double intercalary veins. The venation pattern suggests a possible affinity with Baetovectata excluding Baetungulata, although the general shape of the forewing, particularly the pronounced posterior angle, may indicate a more basal position within the Baetidae lineage. Because the holotype is female, crucial characters of male genitalia and turbinate eyes cannot be verified, and the authors refrained from establishing any new higher taxon above the genus level.

The biogeographic implications are considerable. From the sparse fossil record, it is clear that Baetidae were already diversified during the Cretaceous, with nearly contemporaneous occurrences in Burmese amber, Taimyr amber, and now North America. Earlier hypotheses proposed either a South American primary centre of evolution or a Pangean origin for the family. Given that mayflies have short adult lifespans and depend on freshwater habitats, transoceanic dispersal likely played only a minor role in shaping their current distribution, although proven cases of such dispersal exist between Madagascar and continental Africa. It therefore seems reasonable to conclude that the origin of Baetidae predates the main continental breakup beginning in the Jurassic, an assumption consistent with recent phylogenies of Ephemeroptera that recover the family as one of the basal lineages.

The discovery also highlights how much remains to be learned from understudied amber deposits. While Burmese amber has been intensively investigated and has yielded numerous Baetidae specimens, the North Carolina amber has produced only a handful of described inclusions despite its considerable age. The new fossil represents the oldest known occurrence of the clade Turbanoculata, meaning it sits at or near the base of the lineage that gave rise to every living Baetidae species. Knowledge of the male imago, with its genitalia and turbinate eyes, could provide crucial insights to confirm the precise taxonomic position of Petracloeon within the family and resolve remaining uncertainties about its phylogenetic relationships.

For now, the tiny mayfly sealed in North Carolina amber stands as a quiet but powerful witness to the deep history of one of the world’s most diverse insect families. Its presence in the Cretaceous of North America significantly expands the known distribution range of Baetidae during that period and reinforces the picture of a family that was nearly global tens of millions of years before the continents assumed their modern configurations. As scientists turn fresh attention to the inclusions preserved in this underexplored deposit, more discoveries may follow, each one adding another piece to the puzzle of how mayflies conquered the freshwater habitats of the world.

Subject of Research: A new fossil mayfly species from Late Cretaceous amber in North Carolina, USA, described as Petracloeon carolinensis gen. et sp. nov., the first Baetidae from the Americas' Cretaceous.

Article Title: The first mayfly ( Ephemeroptera , Baetidae ) from Late Cretaceous amber of North Carolina, USA

Article References: Sroka, P., & Gattolliat, J.-L. (2025). The first mayfly (Ephemeroptera, Baetidae) from Late Cretaceous amber of North Carolina, USA. Fossil Record, 28(1), 125-132. https://doi.org/10.3897/fr.28.143974

Image Credits: AI Generated

DOI: 10.3897/fr.28.143974

Keywords: mayfly, Baetidae, Ephemeroptera, Cretaceous amber, North Carolina, fossil, Petracloeon carolinensis, paleontology, biogeography, amber inclusions, Late Cretaceous, insect evolution