Abstract
Asample of 208 specimens from Ctenomys mendocinus-group species (106 females and 102 males) was studied. Five species were included in a comparative cytogenetic and morphometric analysis: Ctenomys flamarioni (N=59), colected between Torres and Estação Ecológica do Taim from Brazil, and. Ctenomys australis (N=47), Necochea and Oriente; C. porteousi (N=38), Bonifacio; C. azarae (N=36), Santa Rosa and Anguil; C. mendocinus (N=28), Mendoza from Argentina. All species showed the same diploid number (2n=48). The karyotypes of C. australis and C. flamarioni were compared through G-, C- and NORs banding techniques. Skull morphology of the five species was analysed using Discriminant Analysis. Chromosomes showed small differences between C. flamarioni and C. australis, while analysis of 18 morphometric variables of skull showed more conspicuous differences among species.