Abstract A paleoparasitological analysis was carried out on a large coprolite assigned to a carnivoran mammal, recovered from the Municipality of Uruguaiana, in the western region of the State of Rio Grande do Sul, Brazil, where the Upper Pleistocene Touro Passo Formation crops out. For this, an individual sample was extracted from the specimen using an electric drill, dissociated with 10% hydrochloric acid solution, washed with distilled water, and sifted through a 500 mesh Tyler sieve. After laboratory processing, the sediment retained on the sieve was mixed with glycerin and examined by optical microscopy, which revealed the presence of 14 protozoan oocysts and three nematode eggs. The morphological characteristics of the oocysts (i.e., spherical shape, thick-walled, internal zygote apparently at the beginning of sporulation, as well as their size) and of the eggs (i.e., ovoidal shape, rounded ends, smooth surface, thin-shelled, embryo in their interior, along with their morphometry) suggest that these specimens belong respectively to the orders Eucoccidiorida and Strongylida (Family Ancylostomatidae) represented by several parasitic species of the alimentary tract of modern carnivore. This is the first record of paleoparasites discovered in a vertebrate host from the Touro Passo Formation.

Abstract Abstract: This study presents the oldest record of Acanthocephala parasite eggs in coprolites preliminary assigned to Crocodyliformes, recovered in the region of Santo Anastácio Municipality, Southwestern São Paulo State. For this, a paleoparasitological investigation was carried out on 53 mineralized coprolites (complete or fragmented), with round shape or cylindrical shape of rounded or pointed ends, 0.2 - 3.9 cm in length x 0.1 - 2.4 cm in diameter, 3.7 grams in weight, and absence of food remains. Individual samples of the surface and internal portions of each coprolite were extracted by electric drill, dissociated with Cloridic Acid 10% solution, washed with Distilled Water, and filtered in granulometric screen Mesh / Tyler 325. After laboratory processing, the sediments retained on the granulometric screen was studied with Glycerin under optical microscopy, and the presence of four Acanthocephala eggs could be observed in sample of only one of these ichnofossils. All specimens were well preserved and showed 72.5 - 85 µm in length x 27.5 - 50 µm in width, elliptical shape, three concentric and thick shells, and embryos in their interior. This study inaugurates investigations and knowledge about Paleoparasitology in Crocodyliformes coprolites from the Bauru Group, Upper Cretaceous from the Paraná Basin.

A Formação Alcântara, uma importante unidade estratigráfica do início do Cenomaniano no Brasil, foi depositada sob condições transicionais (estuarinas), e o seu registro fóssil inclui restos fragmentários de vegetais, peixes, crocodilomorfos, pterossauros e dinossauros, com uma notável diversidade de placas dentárias de dipnoiformes. O material de dipnoiformes aqui reportado compreende um novo taxon, Equinoxiodus alcantarensis gen. et sp. nov. A maioria dos morfótipos de vertebrados continentais coletados na Formação Alcântara são similares a faunas cronocorrelatas do norte da África, mas este novo gênero de Dipnoiformes indica algum grau de isolamento paleogeográfico e endemismo, provavelmente causado pelo alargamento do Oceano Atlântico equatorial no início do Cenomaniano, que pode ter afetado, de forma seletiva, algumas espécies.

The Alcântara Formation, an important stratigraphic unit from the early Cenomanian of Brazil, was deposited under transitional (estuarine) conditions, and its fossil record includes fragmentary remains of plants, fishes, crocodylomorphs, pterosaurs and dinosaurs, with a noteworthy diversity of dipnoiformes tooth plates. The dipnoiformes material reported here comprises a new taxon, Equinoxiodus alcantarensis, gen. et sp. nov. Most of the identified morphotypes of continental vertebrates collected in the Alcântara Formation are similar to chronocorrelative faunas from Northern Africa, but this new genus of Dipnoiformes indicates some degree of paleogeographic isolation and endemism. This was probably caused by the widening of the equatorial Atlantic Ocean during the early Cenomanian, which may have selectively affected some species.