Oxysomatium brevispiculum n. sp. (Nematoda: Cosmocercidae) from Amphisbaena alba Linnaeus (Squamata, Amphisbaenidae) in the Cerrado Biome from Brazil.

In the present study, we describe Oxysomatium brevispiculum n. sp. (Ascaridida: Cosmocercidae) parasitizing Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae) in the municipality of Uberlândia, Cerrado Biome, Minas Gerais, Brazil. Oxysomatium brevispiculum n. sp. differs from its congeners by having shorter spicules and by the number and arrangement of caudal papillae. The males of the new species have a precloacal unpaired papilla and can be easily distinguished from O. caucasicum in which this morphological trait is absent. Oxysomatium brevispiculum n. sp. differs from the other three species of the genus by the number and arrangement of caudal papillae, with 13 pairs + 1 unpaired precloacal papilla, arrangement 8+1:2:3, while O. brevicaudatum has 14-16 pairs +1 unpaired papilla, and 7-9+1:1:6 arrangement, O. petrolinensis has 16 pairs +1 unpaired papilla, and 8+1:1:7 arrangement, and O. dollfusi with 15-16 pairs +1 unpaired papilla, and 8-9+1:1:6 arrangement. Oxysomatium brevispiculum n. sp. is the fifth species of this genus, the second species in a Neotropical host, and the first species of this genus described in amphisbaenid hosts. In addition, the present study provides an identification key for the species of this genus.

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.