Paleoparasitological study of avian trace fossils from the Tremembe? Formation (Oligocene of the Taubat?e Basin), Sa?o Paulo, Brazil

Coprolites are promising tools for the understanding of paleoecological and paleoenvironmental aspects. Through its chemical composition and analysis of micro-and macrostructures, it is possible to obtain information about the diet of ancient animals and insights into the climate and vegetation of paleoenvironments. Paleo-parasitological analysis of these trace fossils help to understand the parasite-host relationship and how parasitic infections were processed in the past. The present study aims to identify helminths in coprolites of the Tremembe ' Formation (Oligocene of the Taubate ' Basin, Sa similar to o Paulo). Furthermore, we included the descriptive association of the paleoparasitological data with the paleoenvironmental information present in the literature for this geological formation. Eggs were identified through linear morphometry and morphology. The paleoparasito-logical analysis revealed the presence of Nematode eggs of Ascaridina, Spirurina, and Trichocephalida, with a prevalence of 5% for each group. The complex life cycle of some nematodes would be made possible by the wide faunal diversity of birds, fish, and arthropods that inhabited the Tremembe ' paleolake. The low prevalence of helminths in the samples may be related to taphonomic processes. This study represents the first paleopar-asitological analysis of avian coprolites from the Tremembe ' Formation. In addition, the finding of these helminth records creates new perspectives for the studies of this geological unit through the epidemiological point of view associated with the local paleofauna and also provides new subsidies for the further development of evolutionary and biogeographic helminth studies.

Automated summary

Coprolites are valuable for understanding ancient ecology and environment through chemical composition and micro-and macroanalysis. A study on coprolites from the Tremembe ' Formation revealed the presence of Nematode eggs, providing insights into parasite-host relationships and ancient parasitic infections. This study contributes to the knowledge on the paleoenvironment of the geological formation.