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| Acarechimys hunikuini Fontoura, Boivin, Marivaux, Antoine, Stutz, Negri, Ribeiro & Kerber, 2024 Artwork by Márcio L. Castro |
ABSTRACT
Caviomorphs are the neotropical hystricognathous rodents (Ctenohystrica: Hystricognathi: Caviomorpha). Octodontoidea are today the richest and most speciose clade of caviomorphs. Their fossil record also reveals a wide array of extinct species, including Acarechimys, a taxon with a widespread South American distribution and extensive temporal range. This genus comprises at least five species documented in deposits ranging from the late Oligocene to the Middle Miocene. Here, we report the discovery of a new species of Acarechimys from Upper Miocene deposits of the Envira River (PRE06 outcrop), situated in the Acre State, western Brazilian Amazonia. The new species differs from the other species of the genus in having lower molars with a strong posterior arm of the metaconid, the presence of a mesostylid (usually prominent) and a neomesolophid forwardly directed and connected to the metalophulid I on m1 but not on m2–3, and the absence of posterior arm of the protoconid. This taxon represents the youngest known species of the Acarechimys lineage to date. Its occurrence in Western Amazonia strengthens support for the hypothesis that South American rodent lineages survived longer during the Neogene at low latitudes than in the southern regions of the continent.
Acarechimys hunikuini
Emmanuelle Fontoura, Myriam Boivin, Laurent Marivaux, Pierre-Olivier Antoine, Narla S. Stutz, Francisco Ricardo Negri, Ana Maria Ribeiro and Leonardo Kerber. 2024. A New Late Miocene stem Octodontoid (Rodentia: Caviomorpha: Octochinchilloi) from the Solimões Formation (Brazil): Paleobiogeographic Implications. Journal of Vertebrate Paleontology. 44(1); e2382822. DOI: doi.org/10.1080/02724634.2024.2382822 [23 Aug 2024]
Pesquisadora da UFSM descreve nova espécie de mamífero extinto
Acarechimys hunikuini recebeu esse nome em homenagem a tribo indígena Huni Kuin que vive na região em que o fóssil foi encontrado
