INVESTIGADORES
EZCURRA Martin Daniel
artículos
Título:
A reappraisal of the taxonomic status of Aetosauroides (Archosauria, Aetosauria) specimens from the Late Triassic of South America and their proposed synonymy with Stagonolepis
Autor/es:
DESOJO, J. B.; EZCURRA, M. D.
Revista:
JOURNAL OF VERTEBRATE PALEONTOLOGY
Editorial:
SOC VERTEBRATE PALEONTOLOGY
Referencias:
Lugar: Lawrence; Año: 2011
ISSN:
0272-4634
Resumen:
The SouthAmerican record of early Late Triassic aetosaurs is composed of two species: Aetosauroides scagliai
and ?Aetosauroides subsulcatus.? Previously undescribed materials belonging to ?Aetosauroides subsulcatus? allow us to reassess
its taxonomy, leading us to consider it a junior synonym of Aetosauroides scagliai. Based on the emended diagnosis of
the species provided here, we recognize that specimens assignable to Aetosauroides scagliai are less common than thought
previously and several of them are not diagnostic beyond indeterminate non-typothorasicine aetosaurins. Previous assignments
of Aetosauroides as a junior synonym of Stagonolepis are not followed because the South American taxon is distinct
due to the presence of a maxilla excluded from the external narial margin, tooth crowns with a straight distal margin and
without a constriction between the root and crown, a gradually convex ventral margin of the dentary, oval fossae ventral to
the neurocentral suture on the lateral sides of the centra, and a ratio between the length and the width between the distal-most
tips of the postzygapophyses equal to or lower than 0.75. The evidence provided here bolsters the validity of Aetosauroides
and extends the distribution of Aetosauroides scagliai into southern Brazil. Although Stagonolepis was employed as an index
taxon for the Adamanian LVF, this genus is currently restricted to Europe and North America. Thus, no overlapping genera
or species of aetosaur are shared between South America and other landmasses. Accordingly, the record of aetosaurs is not
useful for providing biostratigraphical correlations between Late Triassic South American beds and those in other regions.