A new genus and species of arvicolid rodent (Mammalia) from the early Pleistocene of Spain

Abstract

In this paper, a new genus and species of arvicolid rodent is described from the late early Pleistocene levels of the sections of Fuente Nueva 3 (Guadix-Baza Basin, Granada, southern Iberian Peninsula), and Quibas (Murcia, southeastern Iberian Peninsula). The majority of Manchenomys n. gen. molars lacks roots, and the morphology of the first lower molar (m1) is simple, with a short and rounded anteroconid complex and widely confluent triangles four and five (T4 and T5) fields. Molar enamel is predominantly negatively differentiated (Mimomys-type). The third upper molar (M3) is also simple, with a short posterior cap. Manchenomys orcensis n. sp. is described from Fuente Nueva 3, and Mimomys oswaldoreigi Agustí, Castillo & Galobart, 1993 from Gilena 2 and Barranco de los Conejos is recombined as Manchenomys oswaldoreigi n. comb. The chronostratigraphic range of Manchenomys n. gen. covers the upper Matuyama geomagnetic chron, between 1.8 Ma (post-Olduvai subchron) and 0.99 Ma (Jaramillo subchron). Manchenomys n. gen. was possibly derived from a local population of Mimomys tornensis Janossy & Meulen, 1975, an arvicolid species present in older early Pleistocene levels of Spain.