Results of 16 measurements and 7 indices obtained from 130 men and 156 women belonging to three populations of Brazilian Indians are reported. For both males and females the averages fir stature and head breadth are in the middle of the distribution range of values observed in other South American tribes; those for head length and nasal height are relatively low but the averages for sitting height, calf circumference and minimum frontal breadth are high. As for the indices, in both sexes the cephalic and cephalofacial are medium, the Rohrer, jugomandibularis and facial low, and the nasal high when compared with other tribes. Morphological distances between the three Cayapo populations were estimated using Mahalanobis' D2 statistic; they are smaller than those separating different tribes and are not the expected ones when the demographic variables of these groups and the geographic distances between them are considered. The amount of variability as expressed by the coefficient of variation and the prevailing pattern of sexual dimorphism are similar to those observed in other Indian populations.
Despite the large amount of research already performed on genetic polymorphisms in Latin American Indians, not much is known about their morphology. This lack of information is particularly obvious among South American Indians, only some 30 populations having been reasonably well studied anthropometrically so far (Comas, '71).
The present paper reports anthropometric data from three Cayapo Indian populations collected as a part of a multidisciplinary investigation started in 1965. The ultimate aim of these studies is the understanding of their genetic structure, trying to ascertain in what way this structure can influence their genetic variability. Previous analyses of the health status of one of these groups and the demography of all three have been reported (Nutels, Ayres and Salzano, '67; Salzano, '71b). Other medical and genetic information will be published elsewhere.