Paleoparasitological analysis of a coprolite assigned to a carnivoran mammal from the Upper Pleistocene Touro Passo Formation, Rio Grande do Sul, Brazil

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, thickwalled, 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 fi rst record of paleoparasites discovered in a vertebrate host from the Touro Passo Formation.

Paleoparasitological Contributions to the Study on Ancient Infections of Hominids and Other Vertebrates in Brazil: A Review

“…Nematodes were observed in coprolites of cynodonts and other terrestrial tetrapods from the Triassic (Mesozoic Era), collected in Santa Maria Formation (Hugot et al, 2014;Silva et al, 2014;Francischini et al, 2017). Coccidia and Nematodes infecting carnivores from the Quaternary period (Cenozoic Era) were also reported (Cardia et al, 2021). Regarding human remains, studies on pelvic and sacral sediments exhumed from the Sambaqui Jabuticabeira II, municipality of Jaguaruna, State of Santa Catarina, revealed the presence of Nematoda parasitic forms (Iñiguez et al, 2022).…”

“…Although the first paleoparasitological studies were focused on the description of infections in ancient humans (Ruffer, 1910;Szidat, 1944), efforts to identify helminths and protozoans in other vertebrate remains throughout the Phanerozoic eon have been noted in the literature. Reports of parasites in fossils and subfossils are uneven, and records from the Cenozoic are by far the most numerous (Araújo et al, 1981;Ferreira et al, 1989bFerreira et al, , 1991Ferreira et al, , 1992Ferreira et al, , 1993Schmidt et al, 1992;Noronha et al, 1994;Jouy-Avantin et al, 1999;Verde & Ubilla, 2002;Sardella & Fugassa, 2009;Beltrame et al, 2011Beltrame et al, , 2012Beltrame et al, , 2013Beltrame et al, , 2015aBeltrame et al, , b, 2017Beltrame et al, , 2018Beltrame et al, , 2022Fugassa et al, 2013Fugassa et al, , 2022McConnell & Zavada, 2013;Wood et al, 2013Wood et al, , 2019Taglioretti et al, 2015;Sianto et al, 2016;Nunes et al, 2017;Perri et al, 2017;Dentzien-Dias et al, 2018;Leles et al, 2018;Tietze et al, 2019Tietze et al, , 2020Souza et al, 2020;Agustín et al, 2021;Cardia et al, 2021;Oyarzún-Ruiz et al, 2021;Petrigh et al, 2021;Sivkova & Kosintsev, 2021;…”