A new fossil cricetid (Rodentia, Sigmodontinae) from northeastern Brazil with remarks on small mammal extinctions in the tropical Quaternary

Abstract

The rare cricetid rodent Bibimys Massoia, 1980 contains three extant species that are distributed in the lowlands of eastern South America between 35°S and 20°S and distinguished mostly by subtle morphological and genetic features. Several fragmented jaws belonging to this genus were recovered from Late Quaternary deposits located in northeastern Brazil, forming part of a rich archaeological and paleontological small mammal assemblage that has been recovered from caves in the Serra da Capivara, state of Piauí. This material is described herein as belonging to a new species, the most hypsodont member of the genus. The specimens also represent an extralimital occurrence of this sigmodontine, as the nearest extant population of Bibimys is ~1,200 km to the south. Because there are few reliable records of extinct small mammals from the Pleistocene–Holocene transition on the South American continent, in describing this new sigmodontine we extend the records of past biodiversity preserved in the Quaternary deposits of tropical South America. This new species likewise highlights that the Serra da Capivara deposits are promising for understanding the evolutionary history of cricetid rodents.

Pliocene sigmodontine rodents (Mammalia: Cricetidae) in northernmost South America: test of biogeographic hypotheses and revised evolutionary scenarios

“…By contrast, the Venezuelan fossil record firmly indicates that this area was already occupied by a member of the genus by at least the Late Pliocene (around 3.6-2.6 Ma; figure 4). Nonetheless, and taking out the 6), Gruta do Urso (7), Igrejinha (8), Carneiro (9), Lagoa Santa (10), Nossa Senhora Aparecida cave (11), Risso cave (12), Abismo Iguatemi (13), Pilger (14), Sangão (15), Deobaldino Marques (16), Garivaldino (17), La Angostura (18), La Mesada (19), Ruinas Jesuíticas de Lules (20), Cueva Traful 1 (21), Ramallo (22), Cueva del Milodon (23), and Tres Arroyos (24). Constructed from several sources mentioned in the main text.…”

“…Tarija basin [16][17][18]). Therefore, a sharp asymmetry characterizes the Sigmodontinae fossil history, with a long and crucial segment biased to high latitudes and little and late evidence from currently tropical and subtropical huge regions [19][20][21][22].…”

“…Figure 4. Current geographical distribution of the rodent genus Zygodontomys and fossil record attributed to Oligoryzomys and Zygodontomys: Pliocene record from Casa Norte Chiguaje locality (NCC), and other Quaternary fossil recording localities, including Aruba (1), Cariacou and Grenada (2), Saint Vincent (3), Orocual (4), Trinidad (5), Toca da Boa Vista and Lapa dos Brejões (6), Gruta do Urso(7), Igrejinha (8), Carneiro (9), Lagoa Santa (10), Nossa Senhora Aparecida cave(11), Risso cave(12), Abismo Iguatemi (13), Pilger(14), Sangão(15), Deobaldino Marques(16), Garivaldino(17), La Angostura(18), La Mesada(19), Ruinas Jesuíticas de Lules(20), Cueva Traful 1 (21), Ramallo(22), Cueva del Milodon(23), and Tres Arroyos(24). Constructed from several sources mentioned in the main text.…”

Cambios en Las Comunidades De Micromamíferos Durante El Holoceno Tardío–antropoceno en El Sudeste De La Provincia De Buenos Aires (Argentina)

“…B. torresi (véase Pardiñas, 1995aPardiñas, , 1999a, la hipótesis más parsimoniosa a la fecha es considerarlo como representativo de B. torresi. No solo esta tiene distribución actual en la Provincia de Buenos Aires, sino que es la de mayor tamaño de las cuatro especies que se reconocen en el género (Neves et al, 2020).…”

Forest stability during the Holocene in Santa Catarina, southern Brazil revealed by small mammals from Gruta do Presépio

“…During the last two decades, descriptions of numerous Quaternary small mammal assemblages have been published for the country (e.g. de Oliviera et al, 2013;Hadler et al, 2018;Motta et al, 2019;Neves et al, 2017Neves et al, , 2020. However, many of them are limited to taxonomic aspects because they lack, due to the nature of the deposits (e.g.…”