Protozoan parasites of birds from the Tremembé formation (Oligocene of the Taubaté Basin), São Paulo, Brazil.

Objective: To analyze the presence of protozoan parasites in bird coprolites from the Tremembé Formation (Oligocene of the Taubaté Basin).
Materials: Twenty avian coprolites embedded in pyrobituminous shale matrices.
Methods: Samples were rehydrated and subjected to spontaneous sedimentation.
Results: Paleoparasitological analyses revealed oocysts compatible with the Eimeriidae family (Apicomplexa) and one single Archamoebae (Amoebozoa) cyst.
Conclusions: The present work increases the amount of information about the spread of infections throughout the Cenozoic Era and reveals that the Brazilian paleoavifauna played an important role in the Apicomplexa and Amoebozoa life cycles.
Significance: This is the first record of protozoans in avian coprolites from the Oligocene of Brazil. These findings can help in the interpretation of phylogenies of coccidian parasites of modern birds, as certain taxonomic characters observed in the Oligocene Protozoa characterize monophyletic groups in current molecular phylogenetic analyses.
Limitations: None of the oocysts were sporulated; therefore, it is not possible to identify the morphotypes to genus or species.
Suggestions for Further Research: Our results create new perspectives related to biogeographic studies of the parasitic groups described and may improve the understanding of the temporal amplitude of parasitic evolutionary relationships between Protozoans and birds.
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