Unexpected primitive rodents in the Quaternary of Argentina

This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the...

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Detalhes bibliográficos
Autores: Vucetich, María Guiomar, Vieytes, Emma Carolina, Verzi, Diego Hector, Noriega, Jorge Ignacio, Tonni, Eduardo Pedro
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2005
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/80764
Acesso em linha:http://hdl.handle.net/11336/80764
Access Level:Acceso aberto
Palavra-chave:Argentina
Biodiversity
Biogeography
Entre Ríos
Phylogeny
Pleistocene
Rodentia
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descrição
Resumo:This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the most primitive taxon of a clade formed by Dinomyidae-Neoepiblemidae-Heptaxodontidae. Evidence of the close relationships among these families also is presented herein. The new fossils reinforce previous hypotheses about the survival of primitive Brazilian taxa after their extinction in the Pampas and Patagonia of southern South America. They also show that the diversity of caviomorph rodents during the Quaternary was greater than supposed and that an important Quaternary extinction, not previously detected, affected several lineages. With the available evidence, it is not possible to determine if these rodents indicate a warm pulse or a particular biogeographic situation in Entre Ríos.