Phylogenetic relationships of the Triassic theropod Zupaysaurus rougieri from NW Argentina
Title:
Phylogenetic relationships of the Triassic theropod Zupaysaurus rougieri from NW Argentina
Author:
Ezcurra, Martin D. Novas, Fernando E.
Appeared in:
Historical biology
Paging:
Volume 19 (2007) nr. 1 pages 35-72
Year:
2007-03
Contents:
The anatomy and phylogenetic relationships of the Upper Triassic theropod Zupaysaurus rougieri are reviewed. This taxon is represented by a nearly complete skull and fragmentary postcranial remains recovered from the Los Colorados Formation (Norian), NW Argentina. Originally, Zupaysaurus rougieri was considered a basal member of the Tetanurae, but its anatomy closely resembles that of the Coelophysoidea, supporting its nesting within this theropodan subclade. Thus reinterpreted, Zupaysaurus represents the first record of coelophysoids in South America. Phylogenetic analyses perfomed in this study depict Zupaysaurus as a non-coelophysid coelophysoid. Autopomorphic traits of Zupaysaurus include: maxillary-jugal ventral margin forming an obtuse angle in lateral view, tibia with a very deep and caudally open caudal fossa for the reception of an astragalar caudal process. Within the phylogenetic context outlined here, the derived features shared with Tetanurae (e.g. maxillary fenestra, caudally forked ascending ramus of the maxilla) are better interpreted as homoplasies rather than tetanuran derived features.
Journal description