Université de Fribourg

Birds have peramorphic skulls, too: anatomical network analyses reveal oppositional heterochronies in avian skull evolution

Plateau, Olivia ; Foth, Christian

In: Communications Biology, 2020, vol. 3, no. 1, p. 195

In contrast to the vast majority of reptiles, the skulls of adult crown birds are characterized by a high degree of integration due to bone fusion, e.g., an ontogenetic event generating a net reduction in the number of bones. To understand this process in an evolutionary context, we investigate postnatal ontogenetic changes in the skulls of crown bird and non-avian theropods using anatomical...

Université de Fribourg

Adapting spherical-harmonics-based geometric morphometrics (SPHARM) for 3D images containing large cavity openings using ambient occlusion: a study with hermit crab claw shape variability

Ege, Yannic C. ; Foth, Christian ; Baum, Daniel ; Wirkner, Christian S. ; Richter, Stefan

In: Zoomorphology, 2020, p. -

One of the advantages of mesh-based geometric morphometrics (GM) over landmark-based approaches, is that it affords the possibility of the precise examination of highly irregular shapes and complex topographic surfaces. In the case of spherical-harmonic-based GM, the main prerequisite is a completely closed mesh surface, which is often lacking, particularly when dealing with natural objects....

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

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

A non-archaeopterygid avialan theropod from the Late Jurassic of southern Germany

Rauhut, Oliver W. M. ; Tischlinger, Helmut ; Foth, Christian

In: eLife, 2019, vol. 8, p. e43789

The Late Jurassic ‘Solnhofen Limestones’ are famous for their exceptionally preserved fossils, including the urvogel Archaeopteryx, which has played a pivotal role in the discussion of bird origins. Here we describe a new, non-archaeopterygid avialan from the Lower Tithonian Mörnsheim Formation of the Solnhofen Archipelago, Alcmonavis poeschli gen. et sp. nov. Represented by a right...

Université de Fribourg

The oldest Archaeopteryx (Theropoda: Avialiae): a new specimen from the Kimmeridgian/Tithonian boundary of Schamhaupten, Bavaria

Rauhut​, Oliver W.M. ; Foth, Christian ; Tischlinger, Helmut

In: PeerJ, 2018, vol. 6, p. e4191

The iconic primeval bird Archaeopteryx was so far mainly known from the Altmühltal Formation (early Tithonian) of Bavaria, southern Germany, with one specimen having been found in the overlying Mörnsheim Formation. A new specimen (the 12th skeletal specimen) from the earliest Tithonian Painten Formation of Schamhaupten (Bavaria) represents the so far oldest representative of the genus. The...

Université de Fribourg

Cranial shape variation in jacarean caimanines (Crocodylia, Alligatoroidea) and its implications in the taxonomic status of extinct species: The case of Melanosuchus fisheri

Foth, Christian ; Blanco, María Victoria Fernandez ; Bona, Paula ; Scheyer, Torsten M.

In: Journal of Morphology, 2018, vol. 279, no. 2, p. 259–273

Cranial shape variation in jacarean caimanines (Crocodylia, Alligatoroidea) and its implications in the taxonomic status of extinct species

Université de Fribourg

Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs

Foth, Christian ; Rauhut, Oliver W. M.

In: BMC Evolutionary Biology, 2017, vol. 17, p. 236

Archaeopteryx is an iconic fossil that has long been pivotal for our understanding of the origin of birds. Remains of this important taxon have only been found in the Late Jurassic lithographic limestones of Bavaria, Germany. Twelve skeletal specimens are reported so far. Archaeopteryx was long the only pre-Cretaceous paravian theropod known, but recent discoveries from the Tiaojishan...

Université de Fribourg

Preliminary observations on the bone histology of the Middle Triassic pseudosuchian archosaur Batrachotomus kupferzellensis reveal fast growth with laminar fibrolamellar bone tissue

Klein, Nicole ; Foth, Christian ; Schoch, Rainer R.

In: Journal of Vertebrate Paleontology, 2017, vol. 37, no. 4, p. e1333121

The bone tissue of femur, rib, and gastralia from three different individuals of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from southern Germany is studied. The femoral bone tissue comprises laminar fibrolamellar bone tissue throughout and is stratified by three annual growth cycles, indicating that the individual died early in its fourth year of life, at which time it...

Université de Fribourg

Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs

Foth, Christian ; Ezcurra, Martín D. ; Sookias, Roland B. ; Brusatte, Stephen L. ; Butler, Richard J.

In: BMC Evolutionary Biology, 2016, vol. 16, p. 188

Archosauromorpha originated in the middle–late Permian, radiated during the Triassic, and gave rise to the crown group Archosauria, a highly successful clade of reptiles in terrestrial ecosystems over the last 250 million years. However, scientific attention has mainly focused on the diversification of archosaurs, while their stem lineage (i.e. non- archosaurian archosauromorphs) has often...