MORPHOMETRIC ANALYSIS OF MACACA ARCTOIDES AND M-THIBETANA IN RELATIONTO OTHER MACAQUE SPECIES

As a first step in reviewing the classification of the two stump-taile d macaque species, Macaca arctoides and M. thibetana, as compared with other species of the genus Macaca, 72 linear dental and cranial varia bles of 11 macaque species were examined by morphometric analyses. The results indicate that the two stump-tailed species are the largest of the macaques and although rather similar overall, they exhibit signif icant differences in the pattern of variation in most of the five skul l regions as shown by Principal Components and Canonical Variate Analy ses. Euclidean Distances based on Canonical Variate scores indicate th at the females of M. arctoides and M. thibetana are more widely separa ted than eight other pairs of macaque species, and that the separation s of the respective males are greater than those of three other pairs of species. These findings are consistent with FOODEN's classification of the stump-tailed macaques as two separate species (FOODEN, 1976; F OODEN et al., 1985). The present results suggest, as other researchers have proposed on the basis of external features, biochemistry and gen etics, that the two stump-tailed macaque species and M. assamensis are closely related. The results also tentatively imply associations with M. fuscata and M. sylvanus but these require further study. The findi ngs have implications for the assessment of the various Chinese Pleist ocene macaque fossils.