New Species of <i>Rotundomys</i> (Cricetinae) from the Late Miocene of Spain and Its Bearing on the Phylogeny of <i>Cricetulodon</i> and <i>Rotundomys</i>

<div><p>The material of <i>Rotundomys</i> (Rodentia, Cricetinae) from the Late Miocene fossiliferous complex of Cerro de los Batallones (Madrid, Spain) is described and compared with all species currently placed in the genera <i>Rotundomys</i> and <i>Cricetulodon</i>. Both the morphology and size variation encompassed in the collection of specimens from Batallones suggest they belong to a single taxon different from the other known species of these genera. A new species <i>Rotundomys intimus</i> sp. nov. is, therefore, named for it. A cladistic analysis, which is the first ever published concernig these taxa, has been conducted to clear up the phylogenetic position of the new species. Our results suggest that <i>Rotundomys intimus</i> sp. nov. inserts between <i>R. mundi</i> and <i>R. sabatieri</i> as a relatively primitive taxon inside the clade <i>Rotundomys</i>. The new taxon is more derived than <i>R. mundi</i> in having a transversal connection between the metalophulid and the anterolophulid on some m1 but more primitive than <i>R. sabatieri</i> and the most evolved species of <i>Rotundomys</i> (<i>R. montisrotuni</i> +<i>R.bressanus</i>) in its less developed lophodonty showing distinct cusps, shallower valleys, and the presence of a subdivided anteroloph on the M1. The species of <i>Cricetulodon</i> do not form a monophyletic group. As a member of <i>Rotundomys</i>, <i>Rotundomys intimus</i> sp. nov. is more derived than all of these taxa in its greater lophodonty and the complete loss of the anterior protolophule, mesolophs, and mesolophids.</p>