Contextualização taxonômica, tafonômica e morfométrica dos remanescentes ósseos da megamastofauna da Gruta Cuvieri (MG), um sítio paleontológico do Pleistoceno tardio / Taxonomic, taphonomic and morphometric contextualization of the megamastofauna bone remains from Cuvieri Cave (MG), a Late Pleistocene Palaeontological Site.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The limited knowledge regarding the Brazilian megafauna (due to a mainly taxonomist tradition of brazilian paleontologists) and the lack of controlled stratigraphic excavations of paleontological sites in Brazil motivated the excavations of Cuvieri Cave, Minas Gerais, using an unprecedented method of excavation in the country, based on detailed exhumation of paleontological remains. This study examined the fossil material exhumed from one fossiliferous areas of the cave (Locus 3), focusing on the following topics: (1) taxonomic classification and description of the megafauna remains recovered, (2) taphonomic study of this material, and (3) functional analysis of large extinct mammalsforelimbs found in the cave and from other specimens deposited in distinct national museums. The main objective of this study was to increase the knowledge regarding the Brazilian megafauna on these marginalized topics. The taxonomic analysis was intended to identify the bones found in the cave to enable the development of the other parts of the study. The taphonomic analysis were performed to assist the understanding of the formation of the fossiliferous package in Locus 3. Finally, the functional study of the forelimb was performed through morphometric geometric analysis and multivariate statistics applied to the distal region of the humerus of extant and extinct Xenarthra in order to infer the function of the forelimb of some extinct species, namely: Catonyx cuvieri, Eremotherium laurilardii, Glossotherium aff. lettsomi, Nothrotherium maquinense, Ocnotherium giganteum, Holmesina paulacoutoi, Pampatherium humboldti and Valgipes bucklandii. The results of the taxonomic analysis indicated the presence of three specimens of Tapirus terrestris, three of Catonyx cuvieri and one of Valgipes bucklandii, revealing a high density of specimens in the site. Through the taphonomic analysis it was concluded that the fall/trampling of animals within the Locus 3 was very important in the fragmentation and dispersion of the megafauna bones, and also that a potential slow sedimentation favored this process. Finally, the morpho-functional results suggest that the extinct armadillos (Pampatherium and Holmesina) as well as the majority of extinct sloths studied (Catonyx, Glossotherium, Ocnotherium, Valgipes) might have been able to dig occasionally the substrate or only remove small quantities of earth, being neither specialized burrowers nor able to pronounced extension of the forelimb. On the other hand, Eremotherium, unlike the other sloth species, was able to extend its arms, not having the ability to dig the substrate. The results were inconclusive regarding the function of Nothrotheriums forelimb.

ASSUNTO(S)

megafauna xenarthra lagoa santa (mg) morfometria geométrica morphometric geometric análise funcional. lagoa santa (mg) functional analysis. xenarthra megafauna

ACESSO AO ARTIGO

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