Pablo Teta

DEFINITION AND DIAGNOSIS OF A NEW TRIBE OF SIGMODONTINE RODENTS (CRICETIDAE: SIGMODONTINAE), AND A REVISED CLASSIFICATION OF THE SUBFAMILY

A new tribe of sigmodontine rodents is formally defined and diagnosed. The tribe contains the extant genera Abrothrix (including Chroeomys), Chelemys, Geoxus, Pearsonomys, and Notiomys, a group of taxa distributed in the central and southern Andes and lowlands both east and west of the cordillera. The new tribe presents a unique combination of characters including nasals and premaxilla usually projected anterior to the incisors, moderately trumpeted; zygomatic plate with upper free border reduced or obsolete; and third upper molar reduced and sub-cylindrical in out-line with an internal ring-like enamel fossette. Molecular phylogenetic analyses indicate that Abrothrix is sister to a clade containing the remaining genera of the new tribe.

Mammalia, Didelphimorphia and Rodentia, southwest of the province of Mendoza, Argentina

We documented terrestrial micromammal assemblages at five localities of southwestern Mendoza province, Argentina. We added new localities for several of the most uncommon small mammal species of this region (e.g. Loxodontomys micropus and Tympanoctomys barrerae). Two main groups of terrestrial non-volant micromammals are represented in southwestern province of Mendoza: one group is related to the South American arid diagonal, and includes species typically adapted to the xeric environments of the Monte Desert; a second group includes Patagonian and High Andean species. Some Patagonian species reached in the study area their northernmost distributional records (e.g. Abrothrix longipilis, A. olivaceus, Chelemys macronyx, Loxodontomys micropus).

Mammalia, Rodentia, Sigmodontinae, Loxodontomys micropus: new locality records

Daniel Edgardo Udrizar Sauthier 1 Pablo Teta 2 Patricio Wallace 3 Ulyses Francisco Jose Pardinas 1 1 Unidad de Investigacion Diversidad, Sistematica y Evolucion, Centro Nacional Patagonico (CONICET). Almirante Brown s/n, (9210) Puerto Madryn, Chubut, Argentina. E-mail: dsauthier@cenpat.edu.ar 2 Departamento de Ecologia, Genetica y Evolucion, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Avenida Intendente Guiraldes 2160, Ciudad Universitaria, Pabellon II, 4o Piso, (C1428EHA) Buenos Aires, Argentina. 3 Ruta 16 km 5, Lago Puelo, Chubut, Argentina.

Mammalia, Didelphimorphia, Didelphidae, Chacodelphys formosa (Shamel, 1930): range extension

Chacodelphys formosa (Shamel, 1930) is possibly the smallest species of the Didelphimorphia (head and body length = 68 mm, tail length = 55 mm; see Voss et al. 2004). Its distribution is only known from five localities in the east of the Chaco and Formosa provinces, Argentina (Teta et al. 2006). These five localities cover an area of about 10,000 km in the South American Humid Chaco eco-region. According to the criteria of the UICN, Teta et al. (2006) suggested that this species must be considered as Vulnerable.