Cranial anomaly, pathology, or normal variant? Thin parietal bones in ancient Egyptian human remains
Analysis of the absence or presence of some sixty-five (Hauser and DeStephano, 1989) non-metric, or epigenetic, traits of the human cranium is among the tools utilized by physical anthropologists in comparative studies of human skeletal biology and of past and present human population variation. One infrequently occurring condition, thinning of the parietal bones, has posed an enigma for over two centuries. Is the feature an anomaly, pathology, or a normal variant? What, if any, role does genetics play in the expression of thinned parietal bones? Synonyms for the condition are myriad: Malum senile biparietale, senile biparietal atrophy, biparietal, unilateral or symmetrical thinning, developmental thinness, biparietal osteodystrophy, morbus Rokitansky, Depressio biparietalis circumscripta and 'carpet bag skull'. Theories regarding the cause of thinned human parietal bones are equally myriad: senility, pathology, osteoporosis, muscle movement, growth defect, constant pressure and 'completely unknown etiology'. E. Sandifort (1783) is credited with the first detailed description and drawing. Extreme thinning and loss of the diploë, in the area(s) lying midway between the sagittal suture and the parietal prominence and anterior to the parietal foramina, characterize the condition. G. Humphry (1858) reported observing just six cases in Europe: one in England, four in Paris and one in Berlin. G. Elliot Smith (1907) reported observing 70 cases in a single cemetery at the Giza Pyramids, pronouncing the condition, 'common in ancient Egypt'. G. Elliot Smith's (1907) article became, and remains, perhaps the most frequently cited source on thinned human parietal bones, albeit with no formal analysis of Smith's data. To test Smith's (1907) premise, the present study recorded a personal series of over 1,000 ancient Egyptian crania, representing more than 3,000 years of ancient Egyptian history and spanning some 1500km of Nile River geography. The results reveal thinned human parietal bones as being a non-metric cranial trait, presented in virtually all periods of ancient Egyptian history, and from all of Egypt's major geographic regions, at an overall frequency rate of 4.9%, with sample-specific frequency rates ranging from 3.4% to 11.1%. The data further reveal evidence of a genetic component, at some level, underlying the expression of the condition.
Phillips, Stephen Richard, "Cranial anomaly, pathology, or normal variant? Thin parietal bones in ancient Egyptian human remains" (2007). Dissertations available from ProQuest. AAI3292064.