A new record of Lestodon armatus Gervais 1855 (Xenarthra, Mylodontidae) from the Quaternary of southern Brazil and remarks on its postcranial anatomy

ABSTRACT

Mylododontidae (Xenarthra: Folivora) includes ground sloths of medium to large size. Lestodon armatus is a mylodontid that have been found in Pleistocene fossiliferous deposits of South America, with most of its records at the southern portion of the continent. Here, we reported a new specimen assigned to this species recovered from a Quaternary deposit in Caçapava do Sul, southern Brazil. The specimen is composed of cranial fragments, vertebrae, articulated hind limb and pes, as well as other post-cranial elements. We described the post-cranial morphology of this specimen, including some elements not yet described for this species, such as the ossified meniscus, cyamo-fabella, and the fusion of the tibia and fibula. The new record contributes to the knowledge on the anatomy of L. armatus as well as to the study of the diversity of the extinct mammalian fauna from southern Brazil.

KEYWORDS:

• Morphology
• Mylodontidae
• megafauna
• Xenarthra
• Quaternary
• Pleistocene

Acknowledgments

Leopoldo Witeck Neto, who found the specimen and guided the team during the fieldwork. Jean Fernando Nunes for help during the preparation and assistance during the fieldwork; Ane E. Branco Pavanato and Ana Carolina B. Brust for the collaboration in the fieldwork; Guilherme Chiarello for assistance in the identification of the anatomic structures; Ana Maria Ribeiro, who permitted the access to the collection of the Fundação Zoobotânica do Rio Grande do Sul; Jamil Pereira, who permitted the access to the collection of the Museu Coronel Tancredo Fernandes de Mello; Andrés Rinderknecht, who permitted the access to the collection of the Museo Nacional de Historia Natural of Uruguay; both anonymous reviewers, for their valuable comments that improved quality to the manuscript; Universidade Federal de Santa Maria (Edital PRPGP/UFSM 025/2018) for the English grammar review and the Sistema de Concessão de Diárias e Passagens PCDP 003861/18 for the assistance in the travels. LK is supported by Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS 17/2551-0000816-2) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 422568/2018-0). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [001].