Sex-difference in the ossification rate of the appendicular skeleton in Capra pyrenaica Schinz, 1838, and its utility in the sex identification of long bones

The main goal of our work is to quantify differences in the rate of ossification in post-cranial Iberian ibex skeletons, related to sex. Another objective is to improve criteria for assessing the sex of post-cranial bones by combining the degree of ossification of the distal epiphysis and biometrical data. Forty Capra pyrenaica skeletons were examined in order to determine the degree of ossification by means of an Ossification Index. Our results evidence that sexual differences in the rate of ossification become visible at 6 months of age. On average, females complete their bone development 2 years before males do. Finally, by means of lineal classification functions which take into account both biometrical and anatomical criteria, we can achieve, in average, a 95.5% of correct sex discrimination within a sample consisting of ibex metacarpi and metatarsi from individuals aging from <1 to 12 years. Therefore, we conclude that the rhythm of ossification in the post-cranial skeleton of C. pyrenaica may be used as a criterion for assessing the sex of skeletal remains and could be applicable to other dimorphic ungulates. Nevertheless, the results obtained for specimens belonging to a particular population may have limited application to other populations with different medium sizes and living at particular densities within habitats with variable quality.