Abstract

CABRERA, Mario R.  and  LUNA, Carlos A.. Presencia de Trachemys Agassiz, 1857 (Testudines, Emydidae) en el Pleistoceno tardío del centro de la Argentina. Cuad. herpetol. [online]. 2011, vol.25, n.2, pp.37-42. ISSN 1852-5768.

The first fossil record at central Argentina of both the turtle genus Trachemys Agassiz, 1857 and the family Emydidae Rafinesque, 1815 is described. The fossil material, of late Pleistocene - early Holocene age, is composed of the proneural plate, the right pleurals IV and VIII, and fragments of the left pleurals III and IV, parts of the right epiplastron, hyoplastron and hypoplastron, and three indeterminate fragments. These shell elements were discovered at El Silencio Site (30°53'20" S, 62°49'29" W), southern coast of the saline Mar Chiquita Lake, Córdoba province, Argentina, in a siltite level with calcium carbonate intercalations assigned to the Tezanos Pinto Formation, whose deposition occurred between 36000 and 8000 years BP. The fossil record is related to a humid event between 16500 and 15500 years BP that, if marked and temporarily sustained enough, may have favoured the colonization by Trachemys (as well as other vertebrate taxa) during the Pleistocene into this area where the genus do not live today, 220 km far to the west of its present distribution.

Keywords : Fossil turtle; Trachemys; Testudines; Pleistocene-Holocene; Paleoclimate.