Chaetophractus vellerosus (Mammalia: Dasypodidae) in the Ensenadan (Early - Middle Pleistocene) of the southeastern Pampean region (Argentina)

Abstract

The xenarthran fauna recognized for the Ensenadan age is particularly abundant; Dasypodidae comprise approximately 20 % ofthis fauna. Chaetophractus vellerosus is recorded in the Pampean region from the Bonaerian-Lujanian (Middle Pleistocene - Late Pleistocene/Early Holocene) to the present, with a current disjunct distribution (a continuous main area comprising the Gran Chaco and central Argentina, and a secondary area in the coastal region of Buenos Aires Province) attributed to a wider paleodistribution. The material s presented here are from Ensenadan sediments outcropping at Punta Hennengo (General Alvarado County, Buenos Aires Province), that would have been deposited under arid to semiarid climate conditions. These allow extension of the temporal distribution of the species to the Ensenadan in the Pampean region, as well as representing new evidence to test hypotheses of distributional changes related to global climatic variations recognized foy the Quatemary. In this sense, the current disjunct distribution can be interpreted as the result of fundamentally humid recent conditions that resulted in a relict occurrence of the species in coastal areas.