Vertebrate taphonomy and paleoecology in an Upper Pleistocene tank deposit of Paraíba, Brazil: Taphonomic modes, evidence of temporal and spatial resolutions and paleoecological patterns of the Brazilian Intertropical Region

Abstract

Curimatãs Paleontological Site (CPS) preserved one of the most iconic fossil assemblages of Late Pleistocene vertebrates of Brazil. Fossils were collected in a tank deposit,a singular type of Quaternary vertebrate-bearing deposit of South America. In this work, a detailed taphonomic study of the tank assemblage of CPS is presented. This analysis also provides taphonomic and paleoecological data obtained through the application of common multivariate techniques and provides estimates of time- and spatial resolution for tank deposits. The results show that, although the CPS assemblage has experienced an array of taphonomic processes, the long-distance transport was the main process controlling the taphonomic pathway of the thanatocoenosis during the biostratinomic phase, and was responsible for the co-occurrence of other processes, such as abrasion, fragmentation and bioclastic sorting. The origin of the taphonomic modes of vertebrates in the tank deposit of CPS may have been controlled by three major taphonomic phenomena: (i) a taphonomic bias towards the large-bodied size; (ii) long time span of transportation towards the final burial environment; and (iii) some degree of reworking. Furthermore, the analysis of these taphonomic modes supports a previous hypothesis: although taphonomic biases affect the origin of tank assemblages, paleoecological patterns can be preserved with considerable fidelity. The time resolution in tank accumulations is of the order of 10- 3 to 104 years and their spatial resolution seems to be from local to regional.