Exploring trace fossils on megafauna remains from the Quaternary Lagoa da Pedra tank deposit, northeastern Brazil

Abstract

The natural tank deposits of northeastern Brazil, particularly those with sedimentary filling, are notable for preserving extensive Quaternary megafauna fossil remains. While previous studies have primarily emphasized taxonomic aspects, ichnological evidence has also been documented. This study reports new trace fossils on megafauna remains from the Lagoa da Pedra natural tank (state of Pernambuco, Brazil), shedding light on behavioral interactions between megafauna taxa and other organisms. Four distinct traces, corresponding to three ichnogenera (Cubiculum, Nihilichnus, and Machichnus) were identified on post-cranial bones, three from Eremotherium laurillardi and one from Xenorhinotherium bahiense. Holes and pits (Nihilichnus nihilicus) on the radius of X. bahiense and the rib of E. laurillardi, along with furrows and scratches (Machichnus fatimae and M. bohemicus) on the rib of E. laurillardi, are attributed to scavenging activities, likely by carnivores. Additionally, furrows observed on the rib and vertebra of E. laurillardi are associated with dermestid insect pupation (Cubiculum ornatus and C. cooperi). These pupal chambers of dermestid insects (Cubiculum) suggest that the final stage of the dry carcasses, before the final burial, probably happened under the dry phase during the late Pleistocene-early Holocene.