| Abstract: | Estimating sex ratios of fossil bone assemblages is an important step in the determination of demographic profiles, which are essential for understanding the palaeobiology and palaeoethology of any particular species, as well as its exploitation patterns by humans. This is especially true for ibex (Capra ibex), which was a main source of food for hominids during Pleistocene times. Classical methods for determining sexual dimorphism and sex ratio, such as analyses using uni‐ and bivariate plots, are based on an arbitrary fixing of limits between sexes. Here we use a more robust statistical method termed mixture analysis (MA) to determine the sex of postcranial remains (long bones, metapodials and tarsals) from ibex. For the first time, we apply MA to both a modern and a fossil sample of one species, by using metric data taken from (i) a collection of present‐day ibex skeletons and (ii) a Palaeolithic sample of the same species. Our results clearly show that the forelimb (humerus and radius) is more dimorphic than the hindlimb (femur and tibia) and is therefore better suited for sexing ibex. It also appears that metapodials should be used carefully for estimating sex ratios. On the basis of these results, we propose a classification of bone measurements that are more or less reliable for sexing ibex. The results of MA applied to the ibex fossil bones from the Upper Palaeolithic site of the Observatoire (Monaco) lead us to the conclusion that this assemblage consists of a majority of males. The quantitative estimations calculated by the MA make it possible to compare the size of Pleistocene and modern ibex for the whole set of variables used in this study. Copyright © 2006 John Wiley & Sons, Ltd. |
