INVESTIGADORES
PEREZ Maria Encarnacion
artículos
Título:
A new species of Chubutomys (Rodentia, Hystricognathi) from the late Oligocene of Patagonia and its implications on the early evolutionary history of Cavioidea sensu stricto
Autor/es:
PÉREZ, M. E.; KRAUSE, M.; VUCETICH, M. G.
Revista:
GEOBIOS
Editorial:
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Referencias:
Lugar: Paris; Año: 2012 vol. 45 p. 573 - 580
ISSN:
0016-6995
Resumen:
Cavioidea is represented today by Dasyproctidae (agouties), Cuniculidae (pacas), and Caviidae (cavies or
??guinea pigs??, maras, mocos, and capybaras). Cavioidea sensu stricto (Cavioidea s.s.) clusters the extant
and extinct Caviidae together with a diverse assemblage of extinct taxa grouped in the family
Eocardiidae. Recent phylogenetic analyses of this group based on morphological characters corroborated
the monophyly of Cavioidea s.s., but retrieved a paraphyletic arrangement of ??eocardiids?? as successive
sister taxa of the crown-group Caviidae. The late Oligocene (Deseadan South American Land Mammal
Age, SALMA) record of Cavioidea s.s. is relevant because it represents the oldest occurrence of the group,
represented only by very scarce materials of Asteromys punctus and Chubutomys simpsoni. New materials
of Deseadan cavioids are of prime importance to understand the early evolution of this group. The
locality of Punta Nava (northeastern Santa Cruz Province, Patagonia, Argentina) has yielded a fauna
assigned to the Deseadan SALMA, but no rodent remains were known so far. A recent fieldwork in this
locality provided the first findings of fossil caviomorphs, including remains of Cavioidea, Octodontoidea,
Chinchilloidea, and Erethizontoidea. A new species of Cavioidea s.s. from this locality is here described,
and its phylogenetic affinities are evaluated. This new cavioid from the Deseadan SALMA, and the
reinterpretation of the morphology of Chubutomys simpsoni, provide new insights into the early
diversification of Cavioidea s.s. The new species from the late Oligocene, and the high position of
Chubutomys in the phylogeny, draw back the origin of all protohypsodont lineages of Cavioidea s.s. to the
Deseadan SALMA. Furthermore, this suggests that the early evolution of Cavioidea s.s. occurred through a
major diversification pulse larger than previously proposed.