2022/01/06 by Michelle Arnal, María Encarnación Pérez, Luz Marina Tejada Medina +1 · 3 citations
Earth and Planetary Sciences · Environmental Science · #Evolution and Paleontology Studies #Animal Ecology and Behavior Studies #Geology and Paleoclimatology Research
paper · doi:10.1080/08912963.2021.2017916
openalex publication_date 2022/01/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Hystricognath rodents arrived in South America from Africa during the Paleogene. The oldest South American rodents (Caviomorpha) were intensively studied in recent years. One of these assemblages is the caviomorph paleofauna from Santa Rosa, Peru. Their age was originally estimated as ?Eocene. Here, we report new caviomorph fossils from Santa Rosa and review the previously described rodents taking into account new dates and updated caviomorph information. We identified 18 genera and 22 species, including one new genus and species (Vucetichimys pretrilophodoncia gen. et sp. nov.), and two new species (Shapajamys minor sp. nov. and Ucayalimys amahuacensis sp. nov.). All taxa are brachydont, with visible cusps, and thin crests. The Santa Rosa rodents are one of the oldest and the most diverse caviomorph paleofaunas known from low latitudes of South America. Similarities between these caviomorphs and other Paleogene assemblages lead us to propose an early Oligocene age for those rodents from the Yurúa River (Brazil) and a close temporal relationship with the oldest known levels from Contamana. This new biochronological scenario has deep implications in the origin and early evolution of caviomorphs. A middle Eocene? entrance of one or several waves of African rodents arriving in South America is possible.