Abrotrichini

About: Abrotrichini is a research topic. Over the lifetime, 18 publications have been published within this topic receiving 741 citations.

Phylogenetic Relationships and the Radiation of Sigmodontine Rodents in South America: Evidence from Cytochrome b

Abstract: Phylogenetic relationships among South American sigmodontine rodents were examined based on the complete sequence for the mitochondrial cytochrome b gene [1140 base pairs (bp)] for 66 species and between 759 and 1140 bp for an additional 19 species. Thirty-eight South American genera were represented, coming from eight of nine tribes. Outgroups included the North American murid rodents Peromyscus, Reithrodontomys, Scotinomys, and Neotoma, the Old World murine rodents Mus and Rattus, and the geomyoid genera Thomomys, Geomys, Dipodomys, and Perognathus as the most distant outgroup. The South American sigmodontines were supported as a monophyletic lineage. Within this radiation several clear-cut suprageneric groupings were identified. Many of the currently recognized tribal groupings of genera were found fairly consistently, although not always with high levels of bootstrap support. The various tribes could not be linked hierarchically with any confidence. In addition, several genera stand out as unique entities, without any apparent close relatives. The overall pattern suggests a rapid radiation of the sigmodontines in South America, followed by differentiation at the tribal and generic levels.

Definition and diagnosis of a new tribe of sigmodontine rodents (cricetidae: sigmodontinae), and a revised classification of the subfamily

Abstract: 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.