Content area
Full Text
Abstract.-With more than 20 recognized species, Monodelphis is the most species-rich genus of living Didelphidae. Recent research on these opossums revealed additional species from Perú and Venezuela, and herein we describe a new species from the montane forests of the eastern slope of the central Andes in Perú. Monodelphis gardneri, new species, is a small taxon with three black dorsal stripes, more similar in external appearance and cranial features to taxa from eastern Brazil, such as M. theresa or M. americana, than to Andean species, like M. osgoodi. Phylogenetic analyses of cytochrome b gene sequences recovered this new species as closer to M. americana from eastern Brazil than to M. theresa (another species in our analyses with three black dorsal stripes). In spite of this external resemblance, the molecular phylogeny indicates that species with dorsal stripes, including M. americana, M. theresa, and the new species, do not form a monophyletic group. Although weakly supported, a relationship between M. americana and the new species suggests a biogeographic connection between these disjunct distributions, i.e., from eastern Brazil and the eastern versant of the Andes.
Keywords: biogeography, Monodelphis gardneri, systematics, taxonomy
The systematics of the short-tailed opossums of the genus Monodelphis Burnett, 1830 is still poorly known, in spite of recent efforts to summarize generic diversity (Pine & Handley 2008). At least 18 nominal species were recognized in the most recent world's listing of mammals (Gardner 2005), but three new species, M. ronaldi Solari (2004), M. reigi Lew & Pérez-Hernández (2004), and M. handleyi Solari (2007), were subsequently described, and others have been recognized but are still unnamed (see Pine & Handley 2008). Gomes (1991) described three new species in his systematic review of Brazilian forms, but these are nomina nuda (Gardner pers. comm.) because they were never published in the meaning of the Code (ICZN 1999). Currently, no fewer than 22 species are recognized, making Monodelphis the most speciose genus of living didelphids (Voss & Jansa 2009).
In Perú, apart from the two recently described species from lowland forests (Solari 2004, 2007), a third was listed by some authors (Emmons et al. 2001, Solari et al. 2001, Voss & Jansa 2003, Pine & Handley 2008, Pacheco et al. 2009) as a new species present in montane...