A new rodent (Caviomorpha: Dinomyidae) from the upper Miocene of southwestern Brazilian Amazonia

Autor(es)

Kerber, Leonardo ^{[1, 2]} ; Bissaro Junior, Marcos Cesar ^[3] ; Negri, Francisco R. ^[4] ; de Souza-Filho, Jonas Pereira ^[5] ; Guilherme, Edson ^[5] ; Hsiou, Annie Schmaltz ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Santa Maria, CAPPA Ctr Apoio Pesquisa Paleontol Quarta Colonia, Sao Joao Do Polesine - Brazil

^[2] Univ Fed Santa Maria, Programa Posgrad Biodiversidade Anim, Sao Joao Do Polesine - Brazil

^[3] Univ Sao Paulo, Lab Paleontol, FFCLRP, Ribeirao Preto - Brazil

^[4] Univ Fed Acre, Lab Paleontol, Campus Floresta, Cruzeiro Do Sul - Brazil

^[5] Univ Fed Acre, Lab Paleontol, Rio Branco - Brazil

• Tipo de documento: Artigo Científico
• Fonte: HISTORICAL BIOLOGY; v. 30, n. 7, p. 985-993, 2018.
• Citações Web of Science: 11

Resumo

Recently, the fossil record of rodents from southwestern Brazilian Amazonia has been reviewed with regards to its diversity as well as its ecological relationships. In the reviews, the necessity to report new specimens collected with stratigraphic control was stated. Here, a new dinomyid specimen collected during a 2015 expedition to the Niteroi locality, Acre River, is reported. The material is a fragment of skull with the right P4-M1 and the left P4-M2 preserved. The cheek teeth are protohypsodont, a characteristic employed to differentiate Potamarchinae dinomyids from the euhypsodont dinomyids Eumegamyinae and Tetrastylinae.The occlusal surface of the cheek teeth is composed of lophs with interruptions, showing little wear, which suggests that the specimen is not fully ontogenetically developed. The specimen has a unique combination of characters (protohypsodont and pentalophodont cheek teeth, with the leading edges of similar thickness to the trailing edges, and presence of a groove on the bottom of the infraorbital foramen) not present in other known dinomyids, which led us to erect a new taxon. The abundant and diverse fossil record of protohypsodont dinomyids suggests that an important radiative event may have occurred during the middle-late Miocene of northern South America. (AU)

• Processo FAPESP: 11/14080-0 - Os Squamata (Reptilia, Lepidosauria) do Cretáceo e Terciário (Paleogeno/Neogeno) das bacias Bauru, Aiuruoca e Acre: sistemática, evolução e paleoambientes
• Beneficiário: Annie Schmaltz Hsiou
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores