A comparative study of cranial growth in Homo and Macaca Supported in part by USPHS grant DE-02272.

Abstract

This study deals with the postnatal growth and remodeling changes that take place in the cranial bone of Macaca mulatta. Multiple ground sections were prepared throughout each component bone from the calvaria and cranial floor of young, rapidly growing specimens having primary or mixed dentition. These sections were then analyzed for (1) the different types of inward-growing and outward-growing bone tissues present, and (2) the distribution of resorptive and depository periosteal and endosteal surfaces. Using this information, the remodeling history of each bone was reconstructed and the overall growth pattern of the craninum as a whole was determined. The growth changes that characterize the brain case of the monkey were then compared and contrasted with those in Homo. While a number of distinct similarities were observed in their respective growth and remodeling processes, several marked differences were also found. These occurred largely in certain parts of the cranial floor and they appeared to be associated with corresponding differences in the size, configuration, and disposition of the brain in the two species and also with factors related to body posture and facial prognathism.