Acanthocefalan eggs in animal coprolites from archaeological sites from Brazil

Integrating paleoparasitological, paleogenetic, and archaeological data to understand the paleoecological scenario of pre-Columbian archaeological site Gruta do Gentio II, Brazil

Paleoparasitology and paleogenetics is the study parasites in ancient remains from latrines, mummified individuals, and coprolites, that is fossilized or desiccated feces. Paleoparasitological studies in Brazil began with analyses of coprolites from the Gruta do Gentio II (GGII) archaeological site, the oldest site related to the Una ceramist tradition (12,000 to 410 BP), Brazil. The GGII archaeological site contained numerous human burials, lithics, and cultural artifacts such as basketry, ceremonial ornaments, and unique pottery of the Una tradition. Coprolites of GGII were submitted to paleoparasitological, and paleogenetic analyses for parasite identification and coprolite origin. In addition, the archaeological characterization of the GGII site was integrated into paleo analyses for proposing a paleoecological scenario. Five taxa of parasites, including Ancylostomidae, Echinostoma sp., Spirometra sp., and Trichostrongylus sp., and three different morphotypes of Capillariidae were recognized in multiple coprolites that were distributed heterogeneously in several stratigraphical layers. The origin of coprolites was genetically defined as five species of mammals, humans, felines as Panthera onca and Leopardus pardalis, and marsupials as Didelphis albiventris and Philander opossum. This is the first study in Brazil that identified both, parasites and species of animals in Pleistocene/Holocene producers of coprolites with geographical and temporal information. The integration of paleoparasitology, paleogenetics, and archaeology is essential to propose paleoecological scenarios from the past of Brazil.

Prevalence and partial molecular characterization of Gigantorhynchus echinodiscus in free-ranging anteaters (Myrmecophagidae, Edentata) in Mato Grosso do Sul state, Brazil

The genus Gigantorhynchus comprises six valid species that require a terrestrial arthropod as an intermediate host. Cystacanths of G. echinosdiscus were previously reported infecting termites in Brazil. Since southern tamanduas (Tamandua tetradactyla) and giant anteaters (Myrmecophaga tridactyla) primarily feed on ants and termites, they are excellent definitive hosts for this species. This study established the prevalence and partial molecular characterization of G. echinodiscus in both species of anteaters using samples collected during necropsies of wildlife-vehicle collision victims in the state of Mato Grosso do Sul, Brazil. From a total of 40 necropsies, 21 of 34 giant anteaters (61.8 %) and all 6 southern tamanduas (100 %) were positive for Gigantorhynchus echinodiscus. Our findings on prevalence, associated with the fact that all animals had good body condition during necropsy, suggest an ancient relationship between this parasite and anteaters, which was previously demonstrated with the description of acanthocephalan eggs in anteater coprolites from archeological sites. This may be a case of a relatively stable relationship, tending toward a parasite-host balance resulting from long-term coevolution between the species.

New morphological and genetic data of Gigantorhynchus echinodiscus (Diesing, 1851) (Acanthocephala: Archiacanthocephala) in the giant anteater Myrmecophaga tridactyla Linnaeus, 1758 (Pilosa: Myrmecophagidae)

Gigantorhynchus echinodiscus (Diesing, 1851) is a parasite of anteaters in South America. Although described by Diesing in 1851, there is still a lack of taxonomic and phylogenetic information regarding this species. In the present study, we redescribe G. echinodiscus collected from a giant anteater, Myrmecophaga tridactyla Linnaeus, 1758, from the Brazilian Cerrado (Savannah) in the State of São Paulo by light and scanning electron microscopy. In addition, phylogenies were inferred from partial DNA gene sequence of the nuclear large subunit ribosomal RNA gene (28S rRNA). We provide for the first time details of the proboscis with a crown having 18 large hooks and numerous small hooks, a lateral papilla at the base of the proboscis, a ringed pseudo-segmented body, large testes, cemented glands in pairs, and a non-segmented region in the posterior end of the body, which contributed to the diagnosis of the species. Molecular phylogenetic analyses recovered G. echinodiscus forming a well-supported monophyletic group with Mediorhynchus sp., which was congruent with morphological studies that allocate both genera within the family Gigantorhynchidae. In conclusion, the present work adds new morphological and molecular information, emphasizing the importance of adopting integrative taxonomic approaches in studies of Acanthocephala.

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Redescription of Gigantorhynchus echinodischus from Brazilian giant anteater.

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First molecular data of the genus Gigantorhynchus with 28S rRNA partial gene.

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Phylogenetic relationships of Gigantorhynchidae are assessed.

Mitogenomics phylogenetic relationships of the current sloth's genera and species (Bradypodidae and Megalonychidae)

We sequenced the complete mitogenome of 39 sloths (19 Bradypus variegatus, 4 B. tridactylus, 1 B. pygmaeus, 1 B. torquatus, 4 Choloepus didactylus, and 10 C. hoffmanni). A Bayesian tree (BI) indicated a temporal split between Bradypus and Choloepus around 31 million years ago (MYA, Oligocene) and the other major splits within each genera during the Miocene and Pliocene. A haplotype network (MJN) estimated a lower temporal split between the sloth genera (around 23.5 MYA). Both methods detected the ancestor of B. torquatus as the first to diverge within Bradypus (21 for BI and 19 MJN), followed by that of the ancestor of B. tridactylus. The split of B. pygmaeus from the common ancestor with B. variegatus was around 12 MYA (BI) or 4.3 MYA (MJN). The splits among the previous populations of B. variegatus began around 8 MYA (BI) or 3.6 MYA (MJN). The trans-Andean population was the first to diverge from the remaining cis-Andean populations of B. variegatus. The genetic differentiation of the trans-Andean B. variegatus population relative to the cis-Andean B. variegatus is similar to that found for different species of sloths. The mitogenomic analysis resolved the differentiation of C. hoffmanni from the C. didactylus individuals of the Guiana Shield. However, one C. didactylus from the Colombian Amazon specimen was inside the C. hoffmanni clade. This could be the first example of possible natural hybridization in the Amazon of both Choloepus taxa or the existence of un-differentiable phenotypes of these two species in some Amazonian areas.

First paleoparasitological record of acanthocephalan eggs from Northwestern Patagonia (Late Holocene, Argentina)

Eggs representative of an acanthocephalan were found in an ancient fragment of raptor pellet, probably belonged to the barn owl, Tyto alba, from the archeological site named "Epullán Chica cave." This site is a cave located at the southern of Neuquén Province, Patagonia, Argentina. The fragment of pellet was found in a layer with charcoals dated at 1980±80 years B.P. A total of 56 eggs were found. Eggs were brown colored and thick-shelled, and presented four membranes, the outer lightly sculpted. The embryos presented hooks in one extremity. Measurements ranged from 87.5 to 107.5μm long and 50 to 57.5μm wide. Eggs were very well-preserved, and were identified as belonged to Class Archiacanthocephala, Order Oligacanthorhynchida, Family Oligacanthorhynchidae, probably Macracanthorhynchus Travassos, 1917, or an unidentified species. This is the first report of small mammal acanthocephalans from ancient material worldwide.

Lutz's spontaneous sedimentation technique and the paleoparasitological analysis of sambaqui (shell mound) sediments

Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz's spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis.