Integrando tafonomia, paleoicnologia e geomatemática a análises paleontológicas de vertebrados quaternários preservados em cavernas da Região Intertropical Brasileira

Abstract

Following death, an animal's remains take on the characteristics of sedimentary particles and are thus susceptible to all environmental physical, chemical, and biological processes. All of the interactions that these remains underwent are preserved on their surfaces as taphonomic features, which help the understanding of how this organic matter from the biosphere is preserved in the geological record, and ichnological features, which help to infer paleoecological relationships. Due to their practically total isolation from the surface, caves have a high potential for long-term preservation of these fossilized remains among fossiliferous deposits. A wide variety of Quaternary Megafauna can be found in Brazil's caves in the Brazilian Intertropical Region, although many studies do not discuss how to preserve their fossil assemblages. Thus, five fossiliferous assemblages from caves in the Brazilian Intertropical Region were examined from an ichnological and taphonomic perspective for this thesis. The environmental conditions that led to the formation and preservation of fossiliferous assemblages in the caves of Complexo Suíço and F3, in Rio Grande do Norte State, and Toca das Onças, Lapa dos Peixes, and Gruna das Três Cobras, in Bahia State, could be inferred because of taphonomic analyses. Moreover, it was possible to identify three common preservation modes for all caves using cluster and factor analyses. The major group suggested that the bones were quickly buried during biostratinonomy, as evidenced by irregular breaks, absent or light weathering, and absences of abrasion and corrosion. Using factor analyses, it was observed that the primary feature separating the Complexo Suíço and Lapa dos Peixes from the other caves was incrustation. Lastly, the ichnological data allowed the identification of predation and necrophagy marks of carnivorous animals, as well as necrophagy marks from osteophagous insects during the decay processes of soft tissue.