Abstract:

Thirty-three species representing all 14 genera of the South American rodent tribe Phyllotini and five problematic genera are surveyed for 97 multistate and binary dental, cranial, skeletal, external, and male reproductive tract characters. Wagner parsimony analysis confirms Calomys as the most basal phyllotine genus and as currently constituted is likely paraphyletic. The results are consistent with the exclusion of Pseudoryzomys from the phyllotines and the separation of Reithrodon and Neotomys from Holochilus at the tribal level. Several highly differentiated generic groups that include a radiation of altiplano endemics centered on Auliscomys and the largely southern Andean/Patagonian Reithrodon group appear to form a clade. A Graomys generic group that includes Andalgalomys and Eligmodontia is also apparent, but its relationships to other phyllotines is obscured by poorly resolved internal nodes in the more species rich and probably paraphyletic genus Phyllotis. The significance and consequences or more intensive taxonomic sampling are discussed. The taxonomic consequences of the phylogeny are presented.