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Orientador(es)
Resumo(s)
The fossil record of pre-Quaternary continental mammals from Chile remains less well-documented than that of neighboring Argentina and Bolivia. Among the most promising successions is the Miocene Cura-Mallin Formation at Laguna del Laja (37.5 degrees S), which preserves diverse mammalian assemblages spanning nearly 10 million years. One of the rodents previously reported from this locality is Acarechimys, a small octodontoid widely documented in Late Oligocene to Late Miocene continental deposits of South America. However, records from Laguna del Laja were based exclusively on fragmentary and undescribed material, leaving their taxonomic identity uncertain. Here, we describe a Santacrucian (late Early Miocene) occurrence of a caviomorph rodent from Laguna del Laja, represented by a partial mandible preserving m1-m3 and a fragment of the dp4. Dental traits, including a laterally compressed lower incisor and a developed posterior arm of the metaconid, support referral to Acarechimys minutus. This well-dated record provides a stratigraphically constrained occurrence of the species in south-central Chile and narrows the geographic gap between Chilean localities of Chucal in the north and Aysen in the south. The new evidence supports the hypothesis that the Laguna del Laja assemblage was not fully endemic, but rather integrated into the broader Santacrucian biogeographic continuum, reinforcing its value as a key reference point for Neogene faunal and biogeographic studies in the south-central Andes.
Descrição
Palavras-chave
Caviomorpha Cura-Mallin Formation Santacrucian SALMA Biogeographic continuum
Contexto Educativo
Citação
Editora
Elsevier
Licença CC
Sem licença CC