The second known specimen of Monodelphis unistriata (Wagner) (Mammalia: Didelphimorphia), with redescription of the species and phylogenetic analysis

PINE, R.; FLORES, D.; BAUER, K.

ZOOTAXA

MAGNOLIA PRESS

Año: 2013 vol. 3640 p. 425 - 441

1175-5326

Very little information exists concerning taxonomic information and phylogenetic relationshipsof the opossum genus Monodelphis Burnett. Of the clearly distinct named species, the leastinformation is available for M. unistriata (Wagner), one of the world?s most poorly knownspecies of mammals. Extant specimens consist of the Brazilian holotype of a skin now withouta skull and dating from almost 200 years ago, and a second specimen with skin and incompleteskull dating from over a hundred years ago and from Argentina. The most recent publishednotes on the holotype date from well over half a century ago and, all told, such notes, theearliest dating from 1842, add up to a highly fragmentary and contradictory picture. Noobservations whatsoever have ever been published for the second and more complete specimen.Also, no hypotheses have ever been made concerning the intrageneric affinities of M. unistriataand such affinities have also been obscure throughout the genus. Herein, we provide a detailedredescription of M. unistriata, the first published images of specimens, and the first account,beyond the previous few most vague and incomplete remarks, of the morphology of the skull.In an effort to ascertain the phylogenetic affinities of M. unistriata, we performed a combinedmolecular (cytochrome b) and nonmolecular (postcranial, cranial, integument, and karyotypiccharacters) parsimony analysis incorporating 27 species of didelphids, including 11 ofMonodelphis. Our results strongly support the monophyly of Monodelphis, and places M.unistriata as sister group to M. iheringi, among the included species.