1Anthropology, University of Toronto, 2Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig
Thursday 10:30-10:45, Ballroom C
Research in hominoid cranial ontogeny has provided significant insight into the similarities and differences between apes and humans. It is also useful in reconstructing the biology of fossil taxa. This analysis completes the hominoid record of cranial ontogeny with the addition of the Hylobatidae, which has previously been left out of studies. The hominoid sample was then analyzed along with a cercopithecoid, Colobus, to investigate the possibility of a discrete hominoid cranial growth pattern.
Three-dimensional coordinates of 145 landmarks and 313 semilandmarks were measured on CT and surface scans from an ontogenetic sample of crania from Pan, Gorilla, Pongo, Hylobates, Symphalangus, and Colobus. After Procrustes superimposition, principal component analyses were computed in shape and form space. We used regressions of shape coordinates on centroid size to assess within-group ontogenetic and static allometric trajectories.
Results show nearly parallel ontogenetic trajectories within the Hominoidea, which is consistent with previous studies. In the first three principal components of shape space, Pan and Gorilla plot closely together along with Pongo. The Hylobatidae are distinctly different from all great apes. Colobus displays a nearly parallel growth trajectory with hominoids, providing evidence for a generalized cranial growth pattern in catarrhines. With the addition of hylobatids and Colobus, this analysis demonstrates that cranial ontogeny is highly conserved in the Catarrhini. Given the existence of this basic catarrhine growth trajectory, it should be possible in the future to predict fossil taxa morphologies at any stage of growth.
This study is funded by the University of Toronto, NSERC, and the Max Planck Institute for Evolutionary Anthropology.