Thylamys velutinus (Wagner, 1842)

Giarla, T. C., Voss, R. S. & Jansa, S. A., 2010, Species Limits And Phylogenetic Relationships In The Didelphid Marsupial Genus Thylamys Based On Mitochondrial Dna Sequences And Morphology, Bulletin of the American Museum of Natural History 2010 (346), pp. 1-67 : 37-38

Thylamys velutinus (Wagner, 1842)

SYNONYMS: pimelurus Reinhardt, 1851.

DISTRIBUTION: According to Carmignotto and Monfort (2006), Thylamys velutinus , which is only known from a few localities, occurs in Cerrado habitats in the Brazilian states of Goiás, Minas Gerais, and São Paulo; it has also been collected in the Distrito Federal. This species is not known to occur sympatrically with any other congener, although it could be expected to coexist with T. karimii throughout much of its geographic range.

MORPHOLOGICAL DIAGNOSIS: Body pelage bicolored (abrupt line of transition from darker middorsal to paler lateral coloration absent); ventral pelage completely gray based (superficially buffy or whitish) except on chin; plantar pads of manus fused together (concave central palmar surface absent) and almost completely covered with small tubercles (small plantar dermatoglyphs are present at the apex of each pad); manual claws long, extending well beyond fleshy apical pads of digits; tail much shorter than combined length of head and body (LT/HBL X 100 5 79%; N 5 6 [based on measurement data from Carmignotto and Monfort, 2006: table 1]), without pale tip; ventral prehensile surface of tail tip indistinct or absent. Nasal bones usually short, not extending posteriorly behind lacrimals in any examined specimen; lacrimal foramina usually exposed to lateral view anterior to orbit; infraorbital foramen above P3 or above P3/M1 commissure; nasolabial fossa deeply excavated; supraorbital margins rounded or squared, not beaded in any examined specimen; maxillary fenestrae present; crown of second upper incisor (I2) subequal to crown of I3; stylar cusp C consistently present on M1 and M2; metaconule present on M3.

COMPARISONS: Qualitative and morphometric comparisons with Thylamys karimii , the only other member of the subgenus Xerodelphys , were provided by Carmignotto and Monfort (2006). The most consistently useful of these are summarized in the preceding species account.

REMARKS: Although velutinus has always been recognized as a valid species, other forms have been regarded as junior synonyms by authors. Of these, only pimelurus is clearly conspecific ( Tate, 1933; Carmignotto and Monfort, 2006). By contrast, formosa Shamel, 1930, listed as a subspecies of velutinus by Cabrera (1958), is a morphologically distinctive taxon of still-uncertain phylogenetic relationships; it is currently referred to the monotypic genus Chacodelphys (see Voss et al., 2004; Voss and Jansa, 2009).

SPECIMENS EXAMINED (N 5 7): Brazil — Distrito Federal, Brasilia ( OMNH 37216 ), 25 km S Brasilia ( OMNH 22284 ) ; Minas Gerais, Lagoa Santa ( UZM 164 [holotype of pimelurus], 165–168) .