Metachirini Hershkovitz, 1992

Voss, RS & Jansa, SA, 2009, Phylogenetic Relationships And Classification Of Didelphid Marsupials, An Extant Radiation Of New World Metatherian Mammals, Bulletin of the American Museum of Natural History 2009 (322), pp. 1-177 : 110

Tribe Metachirini Hershkovitz, 1992

CONTENTS: Metachirus .

DIAGNOSIS: Metachirini is uniquely distinguished from other members of the subfamily Didelphinae (indeed, from all other didelphids) by contact between the frontal and squamosal on the lateral surface of the braincase.

REMARKS: Although Metachirus could logically be referred to the Didelphini , a new name would then be needed for the clade now awkwardly referred to in the literature as the ‘‘large 2 n 5 22 opossums’’ ( Chironectes , Didelphis , Lutreolina , Philander ). Because many morphological characters unambiguously diagnose the latter group, whereas only a few diagnose the group that includes the large 2 n 5 22 opossums plus Metachirus (see appendix 5), the present arrangement seems preferable. Additionally, because the branch leading to Metachirus is a long one (e.g., in fig. 33), we expect that fossils will eventually be found to occupy it, and that such discoveries will minimally disrupt the suprageneric nomenclature if a tribe is already available to accommodate them.

The name Metachirini was credited by Gardner and Dagosto (2008) to Reig et al. (1985), but no family-group name based on Metachirus fulfills the technical criteria for availability ( ICZN, 1999: Article 13) prior to Hershkovitz (1992b), who effectively diagnosed Metachirinae in a key. By the Principle of Coordination ( ICZN, 1999: Article 36), Metachirini is available with the same authorship and date.