{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T02:24:42Z","timestamp":1784946282434,"version":"3.55.0"},"reference-count":92,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2024,10,15]],"date-time":"2024-10-15T00:00:00Z","timestamp":1728950400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Journal of Anatomy"],"published-print":{"date-parts":[[2025,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Within Xenarthra (Eocene\u2010Recent), Folivora developed (late Eocene\u2010Recent) a remarkable diversity with respect to ecology and taxonomy over its evolutionary history. Knowledge of the diversity achieved by members of this clade in high\u2010altitude areas of South America (i.e., Altiplano and Puna regions of Peru, Bolivia, and northwestern Argentina) has been improved in recent decades. A particular example involves the late Neogene Mylodontidae <jats:italic>Simomylodon uccasamamensis<\/jats:italic>, known mostly from multiple specimens recovered from the Bolivian Altiplano. Although several anatomical descriptions of this ground sloth have been published, almost nothing is known about its ontogenetic development and the associated morphological changes. Here we describe and compare new specimens of <jats:italic>S. uccasamamensis<\/jats:italic> from the upper level of the Tafna Formation (Pliocene) in the eastern Puna (ca. 3800 masl), Argentina, representing the southernmost record of this species. The new material is represented by specimens showing different ontogenetic stages, from infant to adult. One subadult specimen reached an estimated body mass of ca. 232\u2009kg. The comparative study of external and internal morphology (the latter obtained from CT scans and radiography) shows remarkable changes in the mandible and molariforms associated with ontogeny; in addition, evidence suggests that the mfs2\u20103 are the first functional teeth, followed by mf1 and cf1. Based on our body mass estimates (ca. 232\u2009kg.), we inferred an average lifespan of 14\u2009years, 9\u2010month gestation time, and sexual maturation at 4.1\u2009years, quite similar to the values we obtained based on estimated body masses of adult specimens from Bolivia published by previous authors. Along its latitudinal distribution (ca. 14\u00b0\u2009S\u201021\u00b0 S) <jats:italic>S. uccasamamensis<\/jats:italic> co\u2010occurred with other ground sloths (e.g., Megatheriinae, Thalassocninae, and Scelidotheriinae), suggesting niche partitioning. The presence of this medium\u2010sized ground sloth is consistent with the similarity between the faunas of eastern Puna and the Bolivian Altiplano during the Pliocene, which is also concordant with what was observed in other clades, such as Rodentia and Notoungulata.<\/jats:p>","DOI":"10.1111\/joa.14152","type":"journal-article","created":{"date-parts":[[2024,10,15]],"date-time":"2024-10-15T12:29:58Z","timestamp":1728995398000},"page":"171-189","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Ontogeny and associated changes of the extinct sloth <i>Simomylodon uccasamamensis<\/i> (Xenarthra, Mylodontidae) from the Pliocene of the eastern Puna, Argentina"],"prefix":"10.1111","volume":"246","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2609-1783","authenticated-orcid":false,"given":"Sof\u00eda I.","family":"Qui\u00f1ones","sequence":"first","affiliation":[{"name":"Laboratorio de Evoluci\u00f3n de Vertebrados y Ambientes Cenozoicos Centro de Ecolog\u00eda Aplicada del Litoral (CECOAL\u2010CONICET) and Universidad Nacional del Nordeste  Corrientes Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6574-4874","authenticated-orcid":false,"given":"Carlos A.","family":"Luna","sequence":"additional","affiliation":[{"name":"Laboratorio de Evoluci\u00f3n de Vertebrados y Ambientes Cenozoicos Centro de Ecolog\u00eda Aplicada del Litoral (CECOAL\u2010CONICET) and Universidad Nacional del Nordeste  Corrientes Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0331-8068","authenticated-orcid":false,"given":"\u00c1ngel R.","family":"Mi\u00f1o\u2010Boilini","sequence":"additional","affiliation":[{"name":"Laboratorio de Evoluci\u00f3n de Vertebrados y Ambientes Cenozoicos Centro de Ecolog\u00eda Aplicada del Litoral (CECOAL\u2010CONICET) and Universidad Nacional del Nordeste  Corrientes Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9407-7097","authenticated-orcid":false,"given":"Adriana M.","family":"Candela","sequence":"additional","affiliation":[{"name":"Divisi\u00f3n Paleontolog\u00eda Vertebrados, Museo de La Plata, CONICET, Facultad de Ciencias Naturales y Museo Universidad Nacional de La Plata  La Plata Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-2130-9798","authenticated-orcid":false,"given":"Alfredo E.","family":"Zurita","sequence":"additional","affiliation":[{"name":"Laboratorio de Evoluci\u00f3n de Vertebrados y Ambientes Cenozoicos Centro de Ecolog\u00eda Aplicada del Litoral (CECOAL\u2010CONICET) and Universidad Nacional del Nordeste  Corrientes Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,10,15]]},"reference":[{"issue":"4","key":"e_1_2_8_2_1","first-page":"240","article-title":"Mam\u00edferos y aves f\u00f3siles argentinas: Especies nuevas, adiciones y correcciones","volume":"1","author":"Ameghino F.","year":"1891","journal-title":"Revista Argentina de Historia Natural"},{"key":"e_1_2_8_3_1","first-page":"97","article-title":"Sur les \u00e9dent\u00e9s fossiles de l'Argentine. 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