Morphometric Discrimination Between Trinomys Albispinus (Is. Geoffroy, 1838) and Trinomys Minor (Reis & Pessôa, 1995) from Chapada Diamantina, Bahia, Brazil, and the Karyotype of Trinomys Albispinus (Rodentia, Echimyidae)
A morphometric discrimination analysis was performed for Trinomys minor (Reis & Pessôa, 1995) and Trinomys albispinus (Is. Geoffroy, 1838). The samples used in this study are from localities in the Chapada Diamantina, a vast plateau in central Bahia State, Brazil. A specimen recently obtained near the type-locality of Trinomys minor was allocated to T. albispinus by principal component and discriminant analyses and by qualitative pelage traits. The karyotype of Trinomys albispinus is described on the basis of this specimen as 2n=60, NA=116, with two Nucleolar Organizer Regions (NORs) located in the interstitial region of the long arm of chromosome pair 10. The similarity between this karyotype and that previously published for T. minor is interpreted here as evidence that T. minor and T. albispinus are closely related forms, probably at subspecific level. A pattern of karyological similarity is here documented for other species pairs in the genus in which a close relationship has been revealed by mitochondrial DNA data.
