Université de Fribourg

Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria

Ezcurra, Martín D. ; Nesbitt, Sterling J. ; Bronzati, Mario ; Vecchia, Fabio Marco Dalla ; Agnolin, Federico L. ; Benson, Roger B. J. ; Egli, Federico Brissón ; Cabreira, Sergio F. ; Evers, Serjoscha W. ; Gentil, Adriel R. ; Irmis, Randall B. ; Martinelli, Agustín G. ; Novas, Fernando E. ; Silva, Lúcio Roberto da ; Smith, Nathan D. ; Stocker, Michelle R. ; Turner, Alan H. ; Langer, Max C.

In: Nature, 2020, vol. 588, no. 2020-7838, p. 445–449

Pterosaurs were the first vertebrates to evolve powered flight1 and comprised one of the main evolutionary radiations in terrestrial ecosystems of the Mesozoic era (approximately 252–66 million years ago), but their origin has remained an unresolved enigma in palaeontology since the nineteenth century2,3,4. These flying reptiles have been hypothesized to be the close relatives of a wide...

Université de Fribourg

Cranial osteology of the early cretaceous turtle Pleurosternon bullockii (paracryptodira: pleurosternidae)

Evers, Serjoscha W. ; Rollot, Yann ; Joyce, Walter G.

In: PeerJ, 2020, vol. 8, p. e9454

Pleurosternon bullockii is a turtle from the Early Cretaceous of Europe known from numerous postcranial remains. Only one skull has so far been referred to the species. Pleurosternon bullockii belongs to a group of turtles called pleurosternids, which is thought to include several poorly known taxa from the Late Jurassic and Early Cretaceous of Europe and North America. Pleurosternids and...

Université de Fribourg

Neuroanatomy of the spinosaurid Irritator challengeri (Dinosauria: Theropoda) indicates potential adaptations for piscivory

Schade, Marco ; Rauhut, Oliver W. M. ; Evers, Serjoscha W.

In: Scientific Reports, 2020, vol. 10, no. 1, p. 9259

Spinosauridae, a theropod group characterized by elongated snouts, conical teeth, enlarged forelimbs, and often elongated neural spines, show evidence for semiaquatic adaptations and piscivory. It is currently debated if these animals represent terrestrial carnivores with adaptations for a piscivorous diet, or if they largely lived and foraged in aquatic habitats. The holotype of Irritator...

Université de Fribourg

Feeding biomechanics suggests progressive correlation of skull architecture and neck evolution in turtles

Ferreira, Gabriel S. ; Lautenschlager, Stephan ; Evers, Serjoscha W. ; Pfaff, Cathrin ; Kriwet, Jürgen ; Raselli, Irena ; Werneburg, Ingmar

In: Scientific Reports, 2020, vol. 10, p. 5505

The origin of turtles is one of the most long-lasting debates in evolutionary research. During their evolution, a series of modifications changed their relatively kinetic and anapsid skull into an elongated akinetic structure with a unique pulley system redirecting jaw adductor musculature. These modifications were thought to be strongly correlated to functional adaptations, especially to bite...

Université de Fribourg

Notes on the cheek region of the Late Jurassic theropod dinosaur Allosaurus

Evers, Serjoscha W. ; Foth, Christian ; Rauhut, Oliver W.M.

In: PeerJ, 2020, vol. 8, p. e8493

Allosaurus, from the Late Jurassic of North America and Europe, is a model taxon for Jurassic basal tetanuran theropod dinosaurs. It has achieved an almost iconic status due to its early discovery in the late, 19th century, and due to the abundance of material from the Morrison Formation of the western U.S.A., making Allosaurus one of the best-known theropod taxa. Despite this, various...

Université de Fribourg

Late Jurassic theropod dinosaur bones from the Langenberg Quarry (Lower Saxony, Germany) provide evidence for several theropod lineages in the central European archipelago

Evers, Serjoscha W. ; Wings, Oliver

In: PeerJ, 2020, vol. 8, p. e8437

Marine limestones and marls in the Langenberg Quarry provide unique insights into a Late Jurassic island ecosystem in central Europe. The beds yield a varied assemblage of terrestrial vertebrates including extremely rare bones of theropod from theropod dinosaurs, which we describe here for the first time. All of the theropod bones belong to relatively small individuals but represent a wide...

Université de Fribourg

Comparative analysis of the shape and size of the middle ear cavity of turtles reveals no correlation with habitat ecology

Foth, Christian ; Evers, Serjoscha W. ; Joyce, Walter G. ; Volpato, Virginie S. ; Benson, Roger B. J.

In: Journal of Anatomy, 2019, no. 0, p. -

The middle ear of turtles differs from other reptiles in being separated into two distinct compartments. Several ideas have been proposed as to why the middle ear is compartmentalized in turtles, most suggesting a relationship with underwater hearing. Extant turtle species span fully marine to strictly terrestrial habitats, and ecomorphological hypotheses of turtle hearing predict that this...

Université de Fribourg

New insights into the lifestyle of Allosaurus (Dinosauria: Theropoda) based on another specimen with multiple pathologies

Foth​, Christian ; Evers, Serjoscha W. ; Pabst, Ben ; Mateus, Octávio ; Flisch, Alexander ; Patthey, Mike ; Rauhut, Oliver W.M.

In: PeerJ, 2015, vol. 3, p. e940

Adult large-bodied theropods are often found with numerous pathologies. A large, almost complete, probably adult Allosaurus specimen from the Howe Stephens Quarry, Morrison Formation (Late Kimmeridgian–Early Tithonian), Wyoming, exhibits multiple pathologies. Pathologic bones include the left dentary, two cervical vertebrae, one cervical and several dorsal ribs, the left scapula, the left...