FOSSIL MAMMAL ASSEMBLAGES OF THEQUATERNARY FROM RIO GRANDE DONORTE STATE, NORTHEASTERN BRAZIL: DIVERSITY AND TAPHONOMIC AND PALEOECOLOGICAL ASPECTS

Abstract

Quaternary fossil mammals are known from several sites in the Rio Grande do Norte State, Brazil. However, the information regarding the knowledge of this peculiar fauna is mostly taxonomic, while stratigraphic, taphonomic and paleoecological aspects were seldom discussed. This work is a synthesis of the knowledge regarding the fossil mammal occurrences from the Quaternary of Rio Grande do Norte State. Here we offer an up to date list of the mammal fauna and best known sites from Rio Grande do Norte State and discuss several issues related to age, taphonomic and diversity patterns as well as the paleoecological implications stemming from those patterns. The fossiliferous sites of Rio Grande do Norte comprise natural tanks, lakes and carstic and costal deposits. Thirty taxa are known from these sites, including megamammals and several large, medium and small sized mammal species. The differences observed in preservational patterns suggest distinct taphonomic processes acting in distinct deposits. The inferred or known autoecologies for the mammal taxa recorded for the Quaternary of Rio Grande do Norte state suggest the presence of environmental settings comprising grasslands mixed with forest fragments. Nonetheless, these inferences should be considered with caution, as the fossil material on which they were based were collected without proper stratigraphic and taphonomic control. Moreover, the age usually attributed to these deposits (Late Pleistocene) was based on preliminary biostratigraphic correlations pending absolute datings in order to establish a more sound geochronological framework.