Description of a New Tribe of Sigmodontine Rodents (Cricetidae: Sigmodontinae) with an Updated Summary of Valid Tribes and Their Generic Contents

JORGE SALAZAR-BRAVO, ULYSES F. J. PARDIÑAS, HORACIO ZEBALLOS Y PABLO TETA

Occasional Papers Museum of Texas Tech University

Museum of Texas Tech University

Año: 2016

0149-175X

We provide a formal recognition to a tribal level clade composed of Andinomys and Punomys,two extant sigmodontine genera consistently and repeatedly recovered in the phylogenetic analyses of molecular and morphological data. As currently recognized, this tribe is distributed in middle to high elevations in the Andes of Bolivia, Peru, northern Chile, and northwestern Argentina in habitats that range from high elevation grasslands and ecotonal areas to dry Puna. Within this new clade, Punomys appears as the more specialized member as it is fully restricted to rocky outcrops and their immediate surrounding areas at elevations above 4400 m on both sides of the Altiplano. In contrast, Andinomys occupies a broad elevational range (500?4000 m) and multiple habitats, from subtropical mountain forests and semiarid Puna and Prepuna to high altitudinal grasslands. Both taxa share a number of possible synapomorphies (e.g., presence of caudal enlargement of the post-zygapophysis in the second and eighth thoracic vertebrates, unilocular-hemiglandular stomachs with a large corpus and deep incisura angularis, and very similar chromosomal complements) and other diagnostic morphological features. The supratribal phylogenetic relationships of the taxon here named are not resolved even with the moderate amount of molecular data now available. In addition, we present a revised classification for the Sigmodontinae and comment on the content and context of this unique radiation of the Cricetidae.