Taphonomic aspects of the Tamandua tetradactyla Linnaeus, 1758, from the Lapa do Bode cave, Ituacu, Bahia, Brazil

摘要

Caves are environments with unique spaces, which can comprise all kinds of geological formations, besides having a high preservation rate of biological remains. Taphonomy in caves sometimes addresses the preservation state of these remains, their modifier agents and/or their relationship with the fossiliferous deposit. In this work, taphonomic aspects of the Tamandua tetradactyla Linnaeus, 1758 collected in the Lapa do Bode cave, Ituacu, state of Bahia, Brazil, were described. The observed biostratinomic aspects were: abrasion degree, degree of transportability, disarticulation, weathering degree, predation marks, color alteration and corrosion. Regarding the abrasion, long bones such as the right femur, left humerus, left tibia and right tibia presented signs of polishing. Considering the Voorhies Groups, we interpreted that the elements were not transported from their fossilization site after disarticulation. Regarding the articulation degree, most part of the material was categorized as associated. Some pieces, such as vertebrae, tibia, fibula and phalanges were found articulated. In terms of weathering, the damaged state was attributed to the vast majority of specimens. Signs of predation were found in the left ulna. The features found are mostly distributed over the diaphysis of the bones. The coloration and corrosion degree observed in most elements indicate that the individual was deposited on well-drained, iron-rich sediments. The association among the low abrasion degree, the weathering features, the disarticulation degree (mostly associated specimens), the high skeleton completeness and the occurrence of all representative elements of the Voorhies Groups suggests that this individual was fossilized where it died or, if there was transport, this occurred prior to the disarticulation stage, through the transport of the whole carcass. The biogenic marks are related to canids, though the animals which consumed the remains did not effectuate the transport after the individual's disarticulation. Corrosion and color alteration indicate characteristics linked to the same type of sediment on which the fossil was deposited, which was rich in iron and acid.