Taiassuídeos (Mammalia, Artiodactyla) do quaternário da região intertropical brasileira: morfometria cranial e implicações taxonomicas

• Ano de defesa: 2014
• Autor(a) principal: Rafaela Velloso Missagia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Análise morfométrica; Tayassu tajacu; Tayassu pecari; Catagonus stenocephalus; Tayassuidae; Taxonomia; Ecologia; Classificação; Morfologia (Animais); cetaceo; Artiodáctilos
• Link de acesso: http://hdl.handle.net/1843/BUOS-B43LZT

The Tayassuidae (Mammalia, Cetartiodactyla) represents one of the first mammalian immigrants that entered South America during the Great American Biotic Interchange. Two genera are recognized in Brazil: Tayassu Fischer, 1814 with two extant species: Tayassu tajacu (Linnaeus 1758) and Tayassu pecari (Link 1795); and Catagonus Ameghino, 1904 represented by one extinct species, Catagonus stenocephalus (Lund in Reinhardt, 1880). The genus Catagonus exhibits adaptations to cursorial habits on dry and relatively open environments. In contrast, Tayassu is adapted mainly to humid climates and woodland and forest environments. Consequently, the reduction of the open environments due to an increase in the temperature and humidity after the Last Glacial Maximum could explain the extinction of most of the Catagonus species and the retraction of the genus in South America, with the extant species C. wagneri, restricted to the Chacoan region in Paraguay, Bolivia and Argentina. The aim of this study is to (1) characterize and analyze the skull, mandible and teeth morphologic and morphometric characters of South American tayassuids, especially focusing on the Brazilian species; (2) discuss those morphometric differences observed in the tayassuid species registered in Brazil and its taxonomic influence; and (3) analyze a morphometric pattern between fossil and extant representatives of the Tayassu species. The multivariate analysis results showed a temporal morphometric distinction between fossil and recent specimens of both Tayassu species. The discriminant method identified T. pecari and T. tajacu as distinct groups, with C. stenocephalus presenting a greater morphometric proximity to T. pecari than to the other South American species of Catagonus. Taking these results into account, we suggest the following hypothesis: 1- to consider T. pecari and T. tajacu in separate genera; and 2- to take into consideration the taxonomic position of the species C. stenocephalus in another genus. This results reveal the need to carry out an integral approach considering together molecular analyzes, and cranial and postcranial morphologic and morphometric characters to contribute to the elucidation of the taxonomy of the South American tayassuids