Morphometrics of the genus Didelphis (Didelphimorphia: Didelphidae) in Venezuela

We review systematics of genus Didelphis in Venezuela by craniometrical analyses of 93 skulls from adult D. albiventris pernigra, D. a. imperfecta, and D. marsupialis. Adults were sexually invariant for most characters, although males were, in general, larger than females. Complementary morphometric data obtained from literature on D. virginiana from Mexico and D. aurita from Brazil were used for comparisons with Venezuelan taxa. Statistical analyses showed that all samples of D. marsupialis were homogeneous in skull dimensions and that D. a. imperfecta was smaller than other taxa. Size-independent analysis revealed a clear differentiation in shape between D. a. imperfecta and D. a. pernigra. Discriminant functions based on skull parameters allowed us to accurately distinguish D. a. imperfecta from D. a. pernigra and from sympatric populations of D. marsupialis. Results obtained in this study and background information suggest upgrading of D. a. imperfecta to the species level.