Abrotrichini

Abrotrichini, also known as the Andean clade or southern Andean clade, is a tribe of rodents in the subfamily Sigmodontinae. It includes about fifteen species in four genera, distributed in South America from southern Peru to southernmost South America, including the Patagonian steppes. The earliest known fossils are from the Pliocene of Argentina.

==Taxonomy== Abrotrichines were universally placed in the tribe Akodontini until the 1990s, and some were even classified within the genus Akodon. Allozyme studies in the early 1990s first provided evidence for their distinction from Akodontini, and in 1999 a study analyzing sequences of the mitochondrial cytochrome b gene found further evidence for the distinction between Akodontini and this group and proposed the name Abrotrichini for the latter. The name Abrotrichini remained formally unavailable under the International Code of Zoological Nomenclature, however, because their proposal had been conditional. Thus, the clade remained without a valid name and for this reason it was included in Akodontini in the 2005 third edition of Mammal Species of the World. Other phylogenetic studies, which also incorporated nuclear genes, affirmed the distinction between Akodontini and the new group. In 2007, Guillermo D'Elía and coworkers published a full diagnosis of the tribe Abrotrichini, validating the name.