Sexual dimorphism in the mandible of the larger hairy armadillo Chaetophractus villosus (Dasypodidae) from northern Patagonia, Argentina

S.M. SQUARCIA; N SIDORKEWICJ; R. CAMINA; E.B. CASANAVE

BRAZILIAN JOURNAL OF BIOLOGY

Instituto Internacional de Ecologia

Lugar: São Carlos SP - Brasil; Año: 2009 vol. 69 p. 347 - 352

1519-6984

The aim of this paper was to study the sexual dimorphism in adult Chaetophractus villosus (Desmarest, 1804), from northern Patagonia, Argentina. Eight mandibular traits were measured in 37 males and 34 females. Univariate and multivariate morphometric analysis were applied to the data set. Results showed that C. villosus was sexually dimorphic, with higher absolute values corresponding to females. The total length of the mandible was the most important variable to discriminate sexes, followed by the height at the level of the last tooth and body length. The percentages of sex discrimination were high, as they were when a new sample (17 males, 13 females) was tested. Females have larger mandibles than males independently of their larger cranial size. They also showed a higher degree of correlation between variables, suggesting a more stable shape for the mandible than in males.