Zumpano MP and Richtsmeier JT (2002) Growth-related shape changes in the fetal craniofacial complex of humans (Homo sapiens) and pigtailed macaques (Macaca nemestrina): A 3D-CT comparative analysis. American Journal of Physical Anthropology.

This study investigates whether macaques and humans possess a common pattern of relative growth during the fetal period. The fetal populations consist of 16 male pigtailed macaques (mean age 20.5 gestational weeks) and 17 humans (9 males and 8 females; mean age 29.5 gestational weeks). For each individual, three-dimensional coordinates of 18 landmarks on the skull were collected from three-dimensional computed tomographic (CT) reconstructed images and two-dimensional CT axial slices. Early and late groups were created from the human (early mean age 24 weeks, N=8; late mean age 34 weeks, N=9) and macaque populations (early mean age 17.7 weeks, N=7; late mean age 23 weeks, N=9). Inter- and intraspecific comparisons were made between the early and late groups. To determine if macaques and humans share a common fetal pattern of relative growth, human change in shape estimated from a comparison of early and late groups was compared to the pattern estimated between early and late macaque groups. Euclidean Distance Matrix Analysis (EDMA) was used in all comparisons. Intraspecific comparisons indicate that the growing fetal skull displays the greatest amount of change along mediolateral dimensions. Changes during human growth are primarily localized to the basicranium and palate, while macaques experience localized change in the midface. Interspecific comparisons indicate that the two primate species do not share a common pattern of relative growth and the macaque pattern is characterized by increased midfacial growth relative to humans. Our results suggest that morphological differences in the craniofacial skeleton of these species are in part established by differences in fetal growth patterns.

Images from this publication.

Landmarks digitized in this study.
















Growth comparison between macaques and humans. Linear distances that display significant confidence intervals are illustrated on 3D reconstructions of lateral (A), midsagittal (B), and frontal views (C) of a fetal human skull. Solid lines indicate linear distances that are significantly larger in the macaque interval relative to the human interval. Dotted lines indicate linear distances that are significantly smaller in the macaque interval relative to the human interval.