Axel Hungerbühler

• PhD
• Professor of Paleontology & Physical Sciences and Dinosaur Museum Curator at Mesalands Community College

The sacrum – consisting of those vertebrae that articulate with the ilia – is the exclusive skeletal connection between the hindlimbs and axial skeleton in tetrapods. Therefore, the morphology of this portion of the vertebral column plays a major role in the evolution of terrestrial locomotion. Whereas most extant reptiles only possess the two ples...

The genus Machaeroprosopus has long been considered invalid because the type specimen of the Late Triassic phytosaur species, M. validus, has been lost. Re-examination of the primary literature regarding the establishment of the Late Triassic phytosaur genus Machaeroprosopus demonstrates that M. buceros is the correct type species, not M. validus....

The skull anatomy of a new species of the phytosaur Machaeroprosopus is described for the first time on the basis of two specimens from the Upper Triassic Cooper Canyon Formation of Texas. Additional information is provided by a third specimen referred to Machaeroprosopus sp. A paranasal bone, an additional paired element of the narial region, is i...

The dentition of Nicrosaurus kapffi, a phytosaur from the Norian of central Europe, consists of three distinct dental sets in the upper jaw, and two in the mandible. Dental sets are defined by: (1) gradual, linear transformations of dental characters within an array that results in characteristic end members; and (2) the position of each array with...

Two associated partial skeletons, one from the McCarty ranch (MOTTU site 0690) near Kalgary, Texas, Tecovas Formation, and the other from the Petrified Forest Member of the Chinle Formation, outside the Petrified Forest, Arizona, represent the most complete specimens ofPoposaurus gracilis found to date, and increase our understanding of the osteolo...

Mystriosuchus westphali is based on a large, well-preserved cranium and a snout fragment from the Stubensandstein (Norian) of south-west Germany. The hypodigm is redescribed and new or poorly known cranial structures in phytosaurs are discussed. For the first time, the presence of a premaxillary crest is substantiated in a phytosaur. The type speci...

“Zanclodon”arenaceus has been suggested to represent the oldest reliably dated phytosaur. The type and only specimen, a mandibular fragment of an archosaur from the Schilfsandstein (Carnian; Late Triassic) of Southwest Germany, is described in detail for the first time. “Z.”arenaceus is characterized by a great elongation of the mandible and symphy...

The temporal region in Temnodontosaurus trigonodon and Temnodontosaurus platyodon consists of three discrete ossifications. These bones are identified as the supratemporal, bordering much of the temporal opening, and in mid-cheek, the squamosal, which is in contact with the quadratojugal along its ventral margin. Interpretation of the bone in mid-c...

The holotype and only specimen of Paleorhinus (= Arganarhinus) magnoculus is most likely a juvenile, as demonstrated by absolute size and skull proportions such as large orbits, a short snout and a narrow rostrum in comparison with other primitive (non-phytosaurid) phytosaurs. The specimen is the most complete juvenile phytosaur known, and may shed...

The holotype and only specimen of Paleorhinus (= Arganarhinus) magnoculus is most likely a juvenile, as demonstrated by absolute size and skull proportions such as large orbits, a short snout and a narrow rostrum in comparison with other primitive (non-phytosaurid) phytosaurs. The specimen is the most complete juvenile phytosaur known, and may shed...

We present diagnoses for the phytosaur genera Nicrosaurus and Mystriosuchus from the Norian Stubensandstein deposits and describe two new species. Most of the specimens formerly encompassed by the nomen dubium Belodon plieningeri are referred to Nicrosaurus meyeri n. sp., which is distinguished from N. kapffi by a slender, uncrested or partially cr...

The Upper Triassic theropod fossil record from Europe is reviewed in terms of va-lidity of proposed taxa and the stratigraphical distribution of theropod remains. Only three species can presently be regarded as valid: Liliensternus liliensterni (HUENE), (?) Liliensternus airelensis CUNY & GALTON, and Procompsognathus triassicus FRAAS. (?) L. airele...

The dentition of Nicrosaurus kapffi, a phytosaur from the Norian of central Europe, consists of three distinct dental sets in the upper jaw, and two in the mandible. Dental sets are defined by: (1) gradual, linear transformations of dental characters within an array that results in characteristic end members; and (2) the position of each array with...

The Stubensandstein (Upper Triassic, Norian) is a complex system of fluvial deposits in southwest Germany and yields one of the most diverse records of fossil vertebrates from the European continental Triassic. Taphonomic data from 17 partial skeletons of the prosauropod dinosaur Sellosaurus gracilis are presented, with emphasis on a recently redis...

Wir beschreiben hier das fragmentäre Skelett eines Ichthyosauriers von geschätzten acht Meter Länge aus dem Unteren Pliensbachium (davoei-Zone) von Bielefeld. Nach der Größe, massiven Schnauze, straken Bezahnung und weiterer Schädelmerkmale wird das Tier der Gattung Temnodontosaurus zugeordnet. Das Stück ist artlich nicht bestimmbar. Eine kritische...

Die unvollständigen Reste des Axialskeletts eines Ichthyosauriers aus dem mittleren Jura (Bathonium) von Bielefeld-Gadderbaum werden beschrieben und abgebildet. Das Stück befindet sich in der Schausammlung des Naturkunde-Museums in Bielefeld. Obwohl eine sichere Bestimmung nicht möglich ist, wird eine Zuordnung zu Ophthalmosaurus diskutiert.

Peculiarities of F. A. Quenstedt’s taxonomic descriptions are discussed. An understanding was indispensable for an identification of the type series of several species of the ichthyosaurStenopterygius from the Posidonia Shale (Toarcian) of Holzmaden in the University collection of Tübingen.Ichthyosaurus triscissus Quenstedt 1856 is probably a senio...