INSUGEO   12554
INSTITUTO SUPERIOR DE CORRELACION GEOLOGICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A new record of Camelidae from the Pleistocene of Tucumán province, Argentina
Autor/es:
V. TORRES CARRO; D. A. GARCÍA LÓPEZ; P. E. ORTIZ
Lugar:
Mendoza
Reunión:
Congreso; 4th International Palaeontological Congress, Mendoza, Argentina; 2014
Institución organizadora:
Asociación Paleontológica Argentina
Resumen:
The fossil record of late Cenozoic mammals in South America is restricted mainly to the Pampean region of Argentina, establishing the base of the chronologic scale for the last 5 Ma on this subcontinent. Although the record of Quaternary mammals in Northwestern Argentina has been notably increased in the last two decades, the study of camelids in this area is currently in a preliminary stage. Particularly for Tucumán Province, only a few of several fossil mammals recovered from Tafí del Valle Formation have been studied in detail. The fossil camelid here presented (PVL 4741) comes from the area of El Rincón, Tafí del Valle, Tucumán. It consists in an incomplete skull of an adult specimen preserving the palatal region with both post-canine series, most of the right orbit and zygomatic arch, part of the skull vault, and rostrum with the last incisors on each side and the left canine. Among other traits, the skull is characterized by its small size, mesognathic and relatively wide rostrum, deep and narrow posterior palatine notch (choanae), dorsally curved zygomatic body (on jugal), small caniniforms, relatively small premolars, P3 mesiodistally oriented, molars with well-developed styles (particularly the mesostyle), U-shaped lophs, and presence of endostyle on M2. This specimen was compared with known South American camelids. This new record differs from Eulamaops by the presence of a deep palatine notch. Moreover, the small skull, mesognathic rostrum, and small caniniforms represent differences of this specimen regarding Paleolama and Hemiauchenia. Adittionally, it differs from Paleolama by its U-shaped lophs, which are similar to Hemiauchenia, Lama, and Vicugna. This skull also differs from Lama by its smaller size, mesognathic rostrum, lesser development of the mesostyle and narrower M3 (bucolingually), and differs from Vicugna by the greater development of the premaxilla, and the mesiodistal orientation of the P3. Nevertheless, the PVL 4741 resembles Vicugna in the small size of the skull and the mesognathic rostrum. Finally, the proportionally wide rostrum and the curved trajectory of the jugal on the zygomatic arch represent singular traits that were not observed on any other South American camelid. These characters suggest the possibility that this specimen represents a new taxon, although closely related to extant forms. This record constitutes an important contribution in sight of the scarce knowledge of the distribution of camelids and other mammals during the Pleistocene in Northwestern Argentina.