Human and chimpanzee occipital bones are thought to grow and develop in distinctly opposite bone remodeling patterns. Preliminary research examining growth-remodeling fields (GRFs) from the surfaces of the occipital bone in modern humans and chimpanzee indicates this may not be entirely correct. By using vinyl/resin-casting techniques, coupled with scanning electron and reflected-light microscopy, GRF profiles from a cross-sectional sample of humans and chimpanzees have documented the ongoing histological activities that reflect developmental processes through which taxon-specific ontogenetic trajectories alter bone morphology. Surface bone profiles aid in explaining how the posterior skull takes shape, thereby aiding in our understanding of the developmental processes that may contribute to the morphological variation in the posterior skull in humans and chimpanzees. Anat Rec (Part B: New Anat) 283B:14–22, 2005. © 2005 Wiley-Liss, Inc.