A large crested tinamous (Aves, Tinamidae, Eudromia) from the Late Pleistocene of Buenos Aires Province, Argentina

NORIEGA, J. I.; SOIBELZON, L.; BEILINSON, E.; SOIBELZON, E.; DIEDERLE J.M.

Ciudad Autónoma de Buenos Aires

Jornada; XXVI Jornadas Argentinas de Paleontología de Vertebrados; 2012

Universidad de Maimónides

Tinamous are medium-sized ground birds endemic to the Neotropical region. The first record of Eudromia corresponds to an indeterminate species from the Miocene of La Pampa Province, being E. olsoni Tambussi and Tonni, 1985 the only known paleospecies from the Pliocene of Buenos Aires Province. Several records of the extant E. elegans Geoffroy Saint-Hilaire, 1832 come from Pleistocene and Holocene localities of Pampean and Patagonian regions. We report the finding of a large nearly complete specimen of Eudromia (RMP001) deposited at the Repositorio Paleontológico Marcos Paz which includes elements of the fore and hindlimbs, girdles, sternum, and a partial vertebral column. The specimen largely exceeds the size range of living species of the genus. It was collected at ?Vignona Quarry? (34° 54´ 51´´S, 58° 42´ 28´´W) in Marcos Paz from a succession whose lower lithosome is characterized by brown silty clay. The fossil was found near the top of this facies and is assigned to the Lujanian Stage/Age due to an absolute date of 60.050 ± 9.840 BP. Because fossil tinamous are osteologically almost indistinguishable from modern representatives, detailed comparative and metric analyses will be needed to ascertain the specific status. Crested tinamous are inhabitants of open and xeric environments with warm temperate to cold temperate climatic conditions. As the fossil location is more than 250 km east of the eastern distributional limit of the nearest extant species, this geographical outlier can be interpreted as indicative of the expansion of Central or Patagonian grasslands during the IS4.