Early Pliocene Desmaninae (Mammalia, Talpidae) from southern Spain and the origin of the genus Desmana
Издание: Vertebrate Paleontology
Desmaninae (water-moles) are common elements in the late Miocene–Pleistocene mammal assemblages from Europe, but knowledge about this group is still scarce. Here we present the desmanines from several early Pliocene localities of the Granada Basin, southern Spain. The species Desmana marci, sp. nov. is described from the sites Calicasas-3 and 4A, characterized, among other traits, by its slightly molarized p4, enormous P2, strongly molarized P3 and P4, and very large metaconule in the M3. Desmana marci shows a typical Desmana i1, with the enamel extending further down anteriorly than posteriorly, but an Archaeodesmana-like I1, low-crowned and bilobed. Desmana marci is proposed as the oldest species of Desmana; its origin lies in Archaeodesmana baetica, and it is in turn interpreted as the ancestor of Desmana verestchagini. Besides, a desmanine of small size and ascribed to Archaeodesmana cf. getica is identified in Calicasas-5A and Purcal-13. This desmanine forms part of a lineage leading to Archaeodesmana elvirae and Archaeodesmana brailloni; this lineage is characterized by an increase in size and in the molarization of the upper premolars. Desmaninae are identified in all the latest Miocene and earliest Pliocene localities from the Granada Basin, evidencing the existence of permanent water bodies. On the contrary, they are not found in sites of similar age in the Guadix Basin, which would have had more arid conditions. The coincident appearance of A. cf. getica in both basins during the early Ruscinian indicates a change towards more humid conditions in the region, allowing the establishment of permanent water flows in the Guadix Basin.