The Oryzomys subflavus species group, with description of two new species (Rodentia, Muridae, Sigmodontinae)

Resumen

The sigmodontine rodent Oryzomys subflavus (Wagner, 1842) and two new species here described form the so-called Oryzomys subflavus species group of the genus Oryzomys. This group includes species of medium to large size, with tail longer than head and body, dorsal color changing gradually to the ventral parts, long foot of terrestrial/scansorial type, skull with supraorbital crests well developed and convergent, long and narrow incisive foramina, zygomatic plate projected forward, and posterolateral pits of palate included in a large fossa. The two new species, Oryzomys scotti sp.nov. and Oryzomys maracajuensis sp.nov., differ in karyotype, in pattern of the lower molars, in pelage of the dorsum and head, in presence or absence of the sphenoidal strut and of sphenopalatine vacuities. Their main habitats are several vegetal formations of the Cerrado and disturbed Atlantic Forest. The geographical distribution of these three species includes mainly the Cerrado and bordering areas of Atlantic Forest and Caatinga Biomes.