Cranial osteology ofLongosuchus meadeiand the phylogeny and distribution of the Aetosauria

Autor: J. Michael Parrish
Rok vydání: 1994
Předmět:
Zdroj: Journal of Vertebrate Paleontology. 14:196-209
ISSN: 1937-2809
0272-4634
DOI: 10.1080/02724634.1994.10011552
Popis: The aetosaur Longosuchus meadei is known from several specimens from the Upper Triassic (Carnian) of Texas. The structure of the single well preserved skull (TMM 31185-84B) was restudied in light of the appearance of new material of other archosaurs subsequent to Sawin's original (1947) description. In particular, an ossified orbitosphenoid and several structures associated with the nasolacrimal duct system are described and discussed for the first time. Adaptations for herbivory in the Aetosauria include the ventral depression of the jaw joint, the edentulous beak, and the conical, unserrated teeth in later aetosaurs. The increased ossification of the braincase may serve to protect this region during food processing, and the nasolacrimal structures probably are associated with the lateral nasal sinus system widespread in archosaurs and particularly well developed in Longosuchus. The Aetosauria are a robust monophyletic group of Suchia that can be characterized by five synapo-morphies. Aetosaurus...
Databáze: OpenAIRE