Abstract

DESOJO, Julia Brenda  and  BAEZ, Ana María. The postcranial skeleton of Neoaetosauroides (Archosauria: Aetosauria) from the Upper Triassic of west-central Argentina. Ameghiniana [online]. 2005, vol.42, n.1, pp.115-126. ISSN 1851-8044.

The postcranial skeleton of the aetosaur Neoaetosauroides Bonaparte, based on previously studied specimens and additional material, is described herein. The new material consists of proatlas, cervical vertebrae, and appendicular dermal scutes collected in the Los Colorados Formation, Ischigualasto-Villa Unión Basin. All these materials are compared with those of other aetosaur taxa and functionally significant characters of the pelvic girdle and hindlimbs are in particular discussed. This study reveals a great anatomical diversity ( e.g. , differences in degree of pelvic expansion, femoral flexure, and crural and tarsal morphology) and suggests that Aetosauria might have included semi-erect and erect forms. This possible spectrum of locomotor postures, together with their wide size range, support previous propositions of more varied lifestyles among aetosaurs than traditionally recognized.

Keywords : Archosauria; Aetosauria; Triassic; Ischigualasto-Villa Union Basin; Los Colorados Formation; Argentina.