Computed Tomography of the Appendicular Skeleton and Arboreal Adaptations of Bradypus variegatus
DOI:
https://doi.org/10.22456/1679-9216.150901Palavras-chave:
common sloth, tomography anatomy, suspensory locomotion, musculoskeletal adaptation, xenarthran morphologyResumo
Introdução: A preguiça-de-garganta-marrom (Bradypus variegatus) é um mamífero arborícola cuja locomoção suspensória na região amazônica requer adaptações morfológicas específicas. O esqueleto apendicular é crucial para esse estilo de vida, mas uma descrição detalhada usando tomografia computadorizada (TC) é escassa. Este estudo teve como objetivo descrever as características anatômicas do esqueleto apendicular de B. variegatus usando TC, correlacionando os achados com seus hábitos arborícolas e suspensórios. Materiais, Métodos e Resultados: Este estudo descritivo foi conduzido usando nove cadáveres congelados de B. variegatus (6 machos jovens e 3 fêmeas jovens). Os animais foram submetidos à tomografia computadorizada helicoidal em decúbito dorsal com os membros estendidos. Reconstruções multiplanares e renderização tridimensional de volume foram usadas para análise anatômica. Os resultados mostraram que os membros torácicos eram maiores que os membros pélvicos. A escápula apresentou uma margem dorsal convexa e uma espinha escápula bem definida. A clavícula não foi identificada. O úmero era um osso longo e cilíndrico, e o rádio e a ulna eram completamente separados por um espaço interósseo distinto. O carpo consistia em cinco ossos dispostos difusamente, e os metacarpos e falanges eram adaptados para suportar garras longas. No membro pélvico, o fêmur apresentava uma diáfise levemente curvada, e a patela não foi observada. A tíbia e a fíbula também apresentavam um espaço interósseo. A pelve era caracterizada por um acetábulo arredondado e profundo, uma tuberosidade isquiática fina e um púbis com amplitude lateral. O sacro tinha seis vértebras articulando-se com o ílio. Discussão: As características morfológicas descritas, como o maior desenvolvimento dos membros torácicos, a ausência de clavícula, o acetábulo profundo e as adaptações dos ossos pélvicos, estão diretamente associadas à locomoção suspensória e à vida arbórea de B. variegatus. Essas características fornecem estabilidade corporal e inserção muscular eficiente para escalar e pendurar-se em troncos de árvores. Os resultados corroboram a hipótese de que o esqueleto apendicular desta espécie reflete uma evolução adaptativa ao seu nicho ecológico único. Este estudo fornece uma base anatômica detalhada que pode subsidiar futuros estudos clínicos, cirúrgicos e radiográficos comparativos nesta espécie.
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Copyright (c) 2026 Michel Santos Cunha, Daniel Furtado Perdigão, José Gonçalo Monteiro Campos, Thiago da Silva Cardoso, Lucas Santos Carvalho, Luisa Pucci Bueno Borges, Sheyla Farhayldes Souza Domingues, Érika Renata Branco, Francisco Décio Oliveira Monteiro, Pedro Paulo Maia Teixeira
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