IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
artículos
Título:
The Chañares Formation: a window to a Middle Triassic tetrapod community
Autor/es:
MANCUSO A. ; GAETANO L.; LEARDI, J.M. ; ABDALA, F. N. ; ARCUCCI A.B.
Revista:
LETHAIA
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2014 vol. 47 p. 244 - 265
ISSN:
0024-1164
Resumen:
The Chañares Formation is known worldwide for its diverse and
well-preserved Ladinian non-marine tetrapod assemblage, including a wide
variety of archosauriform reptiles (proterochampsids, early offshoots
of the crocodilian line and dinosaurian precursors) and synapsids
represented by dicynodonts and cynodonts. This tetrapod record offers an
opportunity to evaluate, within a taphonomic context, the palaeoecology
of this Middle Triassic fauna. The taphonomic analysis of the Chañares
assemblage, under precise stratigraphical control, indicates that it is a
good representation of the original faunal composition allowing us to
address the palaeoecological interactions between its components. Mass
estimations and morphology-based palaeobiological inferences of Chañares
tetrapods are used to reconstruct the trophic structure of the
community. Chañares tetrapod fauna was numerically dominated by
middle-sized herbivorous and small faunivorous cynodonts, whereas
middle-sized faunivorous cynodonts and large dicynodonts were less
common. In contrast to the therapsids, which show a low species-richness
and high abundance, the archosauriforms are less abundant, but are the
most taxonomically diverse group. The large paracrocodylomorphs
(estimated body masses between 350 and 500 kg) are identified as the top
predators of the community, and the traversodontid cynodonts and
dicynodonts (estimated body masses reaching approximately 43 and 360 kg,
respectively) are indentified as the base herbivores of the trophic
pyramid. We conclude that the worldwide faunal composition in the
Ladinian reveals two continental assemblages: an eastern Laurasian
assemblage dominated by temnospondyl amphibians; and a western Gondwanan
assemblage dominated by therapsids but including a wide diversity of
archosauriforms.