Benjamin P. Kear

Uppsala University | UU · Museum of Evolution

Despite its relatively limited vertebrate fossil record, Syria currently records the largest number of documented Mesozoic marine reptile occurrences among the Middle Eastern countries. In particular, the phosphatic deposits of the Palmyrides mountain chain have yielded fossils of aquatic squamates, bothremydid and chelonioid marine turtles, as wel...

The emergence of gigantic pliosaurid plesiosaurs reshaped the trophic structure of Mesozoic marine ecosystems, and established an ~80 million-year (Ma) dynasty of macropredatory marine reptiles. However, the timescale of their ‘defining’ trait evolution is incompletely understood because the fossil record of gigantic pliosaurids is scarce prior to...

In 2020, the Australasian palaeontological association Australasian Palaeontologists (AAP) joined the Australian government-supported Australian National Species List (auNSL) initiative to compile the first Australian Fossil National Species List (auFNSL) for the region. The goal is to assemble comprehensive systematic data on all vertebrate, inver...

Reptiles first radiated into oceanic environments after the cataclysmic end-Permian mass extinction (EPME)1, 251.9 million years (Ma) ago. The geologically oldest fossils evincing this adaptive transition have been recovered from upper-Lower Triassic (lower Spathian) strata, ∼248.8 Ma2, and postdate a landmark turnover of amphibian-dominated to rep...

Reptiles first radiated into oceanic environments after the cataclysmic end-Permian mass extinction (EPME)1, 251.9 million years (Ma) ago. The geologically oldest fossils evincing this adaptive transition have been recovered from upper-Lower Triassic (lower Spathian) strata, ∼248.8 Ma2, and postdate a landmark turnover of amphibian-dominated to rep...

The early Tournaisian (Carboniferous) stage represents a key episode in the evolution of vertebrates. It follows the end-Devonian Hangenberg extinction event, which led to a major perturbation to both terrestrial and aquatic vertebrate ecosystems, and resulted in a significant restructuring of assemblages. However, few faunal associations of this a...

Benjamin P. Kear [benjamin.kear@em.uu.se], Museum of Evolution, Uppsala University, Uppsala, 752 36, Sweden.

The evolution of Australia’s distinctive marsupial fauna has long been linked to the onset of continent-wide aridity. However, how this profound climate change event affected the diversification of extant lineages is still hotly debated. Here, we assemble a DNA sequence dataset of Macropodoidea—the clade comprising kangaroos and their relatives—tha...

Australian dinosaur research has undergone a renaissance in the last 10 years, with growing knowledge of mid-Cretaceous assemblages revealing an endemic high-paleolatitude Gondwanan fauna. One of its most conspicuous members is ankylosaurs, which are rare but nonetheless occur in most Australian dinosaur-bearing formations spanning the uppermost Ba...

The evolution of Australia’s distinctive marsupial fauna has long been linked to the onset of continent-wide aridity. However, how this profound climate change event affected the diversification of extant lineages is still hotly debated. Here, we assemble a DNA sequence dataset of Macropodoidea — the clade comprising kangaroos and their relatives —...

Sharks are iconic predators in today’s oceans, yet their modern diversity has ancient origins. In particular, present hypotheses suggest that a combination of mass extinction, global climate change, and competition has regulated the community structure of dominant mackerel (Lamniformes) and ground (Carcharhiniformes) sharks over the last 66 million...

The mid-Cretaceous (Albian and Cenomanian, 113–93.9 Myr) marked a transformative interval of shark evolution during which lamniforms (mackerel sharks) diversified as dominant marine predators. Yet, their radiation dynamics relative to major biotic turnovers delimiting the Albian–Cenomanian and Cenomanian–Turonian boundaries are incompletely underst...

The record of Cretaceous pterosaur remains from Germany is sparse. The material recovered to date includes the fragmentary holotypes of Targaryendraco wiedenrothi and Ctenochasma roemeri, as well as a few isolated pterodactyloid teeth and some indeterminate skeletal elements, together with a plaster cast of a large Purbeckopus manus imprint. Here,...

Sharks (Selachimorpha) are iconic marine predators that have survived multiple mass extinctions over geologic time. Their prolific fossil record is represented mainly by isolated shed teeth, which provide the basis for reconstructing deep time diversity changes affecting different selachimorph clades. By contrast, corresponding shifts in shark ecol...

During the Cenomanian–Turonian transition (∼94 Ma), what is today Central Russia formed part of the northern epicontinental margin of the Tethys Ocean. Diverse marine vertebrate faunas inhabited these palaeoenvironments, but their fossils are incompletely documented. Here, we report the discovery of marine reptile remains, recovered together with p...

Tanius sinensis was one of the first dinosaur species to be named from China. It was established on a partial skeleton recovered by a joint Sino-Swedish expedition in 1923. The fossils were excavated from Upper Cretaceous strata of the Jiangjunding Formation (Wangshi Group) in Shandong Province, and although their discovery dates back almost 100 ye...

Axial and appendicular measurements

Figures of bite mark and additional indeterminate Hadrosauroid remains

Trematosaurids were globally distributed Early Triassic temnospondyl amphibians characterized by elongate ‘crocodile-like’ skulls. Some of the most famous trematosaurid fossils were discovered on the island of Spitsbergen in the Arctic Svalbard archipelago. Among these, the short-snouted trematosaurine, Tertrema acuta, is one of the few taxa repres...

The prevalence of injuries in fossil populations over evolutionary time scales can elucidate intrinsic and extrinsic factors affecting organism health, and shed light on ancient ecosystems and organismal palaeobiology. We used ichthyosaurs as a model system to examine factors affecting the prevalence of osteopathologies, surveying 624 specimens fro...

In this study, a new assemblage of Ediacaran metazoan fossils is reported from the basal Stáhpogieddi Formation on the Digermulen Peninsula of Arctic Norway, including Anulitubus n. gen. Moczydłowska in Moczydłowska et al., Anulitubus formosus n. gen. n. sp. Moczydłowska in Moczydłowska et al., Coniculus n. gen. Moczydłowska in Moczydłowska et al.,...

Thalassomedon haningtoni is one of the most completely preserved elasmosaurid plesiosaurians described to date. Unlike most other elasmosaurid fossils, both the holotype and a second referred specimen — which were recovered from the middle Cenomanian Graneros Shale in the mid-western USA — are represented by intact skulls with articulated postcrani...

Sharks (Selachimorpha) are iconic marine predators that have survived multiple mass extinctions over geologic time. Their fossil record is represented by an abundance of teeth, which traditionally formed the basis for reconstructing large-scale diversity changes among different selachimorph clades. By contrast, corresponding patterns in shark ecolo...

Benjamin P. Kear [benjamin.kear@em.uu.se], Museum of Evolution, Uppsala University, 752 36 Uppsala, Sweden. ISSN 0311-5518.

It is thought that dinosaurs laid hard-shelled eggs, whereas ancient marine reptiles gave birth to live young. However, new discoveries of fossilized soft-shelled eggs challenge these long-held tenets of reproductive evolution. Fossilized soft-shelled eggs challenge current views about dinosaurs.

The world-famous upper Miocene fossil localities on the Aegean island of Samos in Greece have produced a rich fossil record that sheds light on the evolution of eastern Mediterranean terrestrial faunas over a one-million-year interval of the late Neogene. Fossils have been discovered on Samos since antiquity, although a succession of paleontologica...

Aim To determine the effects of competition and divergence time on morphological dissimilarity and geographical range overlap between dasyurid species at both regional and local scales. Our hypothesis is that speciation in this group has been largely allopatric at regional scale, but involved morphological divergence at local scale through sympatri...

Changing predator-prey interactions during the Mesozoic Marine Revolution (MMR) profoundly altered the trajectory of marine tetrapod evolution. Here, we assess potential signatures of this landmark transition through the fossil record of skeletal pathologies in ichthyosaurs — iconic marine reptiles that developed increasingly ‘fish-like’ body plans...

The Turonian (93.9–89.8 Ma) was a key transitional interval of plesiosaur evolution, during which pliosaurid apex predators (dominant since the Middle Jurassic) rapidly declined, and polycotylids correspondingly radiated as middle trophic-level pursuit hunters. Paradoxically, however, the fossil record of Turonian plesiosaurs is globally sparse, es...

Here, we describe part of a large-bodied macrophagous plesiosaur jaw from the lower Bajocian (Middle Jurassic) Passwang Formation near Arisdorf in the Basel-Land canton of Switzerland. The specimen preserves the posterior glenoid extremity of the right mandibular ramus comprising the surangular, angular, articular, and probably the prearticular. No...

Exceptionally preserved Mesozoic feathered dinosaur fossils (including birds) are famous, but recognized from only very few localities worldwide, and are especially rare in the Southern Hemisphere. Here we report an assemblage of non-avian and avian dinosaur feathers from an Early Cretaceous polar (around 70°S) environment in what is now southeaste...

Fossilized eyes permit inferences of the visual capacity of extinct arthropods1–3. However, structural and/or chemical modifications as a result of taphonomic and diagenetic processes can alter the original features, thereby necessitating comparisons with modern species. Here we report the detailed molecular composition and microanatomy of the eyes...

Palaeoepidemiological studies related to palaeoecology are rare, but have the potential to provide information regarding ecosystem-level characteristics by measuring individual health. In order to assess factors underlying the prevalence of pathologies in large marine vertebrates, we surveyed ichthyosaurs (Mesozoic marine reptiles) from the Posidon...

In stark contrast to the famously rich Jurassic fossil record, the documented occurrences of Cretaceous pterosaur remains from Germany are extremeley sparse. To date, only a few bones and footprint traces have been found in strata of Berriaisian–Hauterivian age. The most complete and best-preserved of these specimens is the holotype of ‘Ornithochei...

In stark contrast to the famously rich Jurassic fossil record, the documented occurrences of Cretaceous pterosaur remains from Germany are extremeley sparse. To date, only a few bones and footprint traces have been found in strata of Berriaisian–Hauterivian age. The most complete and best-preserved of these specimens is the holotype of ‘Ornithochei...

Cretaceous pterosaur fossils are rare in Germany. The specimens documented to date are limited to only a few fragmentary body fossils and footprint traces from different Lower Cretaceous strata. Here we add to this sparse, but palaeobiogeographically significant record with the description of an incomplete mandible from marine sediments of the lowe...

Living kangaroos, wallabies and rat-kangaroos (Macropodoidea) constitute the most ecologically diverse radiation of Australasian marsupials. Indeed, even their hallmark bipedal hopping gait has been variously modified for bounding, walking and climbing. However, the origins of this locomotory adaptability are uncertain because skeletons of the most...

From an initial isolated position as the oldest evolutionary prototype of a bird, Archaeopteryx has, as a result of recent fossil discoveries, become embedded in a rich phylogenetic context of both more and less crownward stem-group birds. This has prompted debate over whether Archaeopteryx is simply a convergently bird-like non-avialan theropod. H...

Choristodera is a clade of extinct aquatic reptiles whose fossils have been found in freshwater and marginal marine deposits from Europe, Asia and North America. The European record is the most extensive, spanning at least the Middle Jurassic to early Miocene, and incorporates the stratigraphically oldest and youngest members of the group. Despite...

Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early...

Choristodera is a clade of extinct aquatic reptiles whose fossils have been found in freshwater and marginal marine deposits from Europe, Asia and North America. The European record is the most extensive, spanning at least the Middle Jurassic to early Miocene, and incorporates the stratigraphically oldest and youngest members of the group. Despite...

The holotype (KUVP 1301) of Styxosaurus snowii—one of the earliest described elasmosaurid plesiosaurians—consists of a well-preserved cranium, mandible and articulated sequence of anterior–mid-series cervical vertebrae found in the lowermost Campanian strata of the Smoky Hill Chalk Member in the Niobrara Formation of Kansas, USA. This particular sp...

Paleopathologies document skeletal damage in extinct organisms and can be used to infer the causes of injury, as well as aspects of related biology, ecology and behavior. To date, few studies have been undertaken on Jurassic marine reptiles, while ichthyosaur pathologies in particular have never been systematically evaluated. Here we survey 41 spec...

MeshLab is an open source system for processing and editing 3D triangular meshes. The install file can be downloaded from http://www.meshlab.net/#download. Versions for Win 64, MacOS, and Linux are available. In order to view a mesh, drag and drop it into Meshlab or open it via the File menu, option Import mesh. Meshlab will automatically display t...

3D Photogrammetric reconstruction of SMNS 15950 showing the pathological area in the skull at the left premaxilla, maxilla and dentary (Fig 5b and 5c–5f). (PLY)

Percentage of completeness of the specimens of Temnodontosaurus from the museum collections, according to its anatomical units. (XLSX)