Skull is one of the most cliché symbols. It represents both power and mortality and has been preserved for scientific and artistic purposes. It is very important in terms of forensic anthropology to tell the biological profile of the deceased: sex, age, and ancestry. And on the other hand, it has significant yet different meaning in cultures. In other words, skull or head sometimes symbolizes as a person, and sometimes merely as a thing. In this following entries, together with the next, I will endeavor to illustrate and discuss the meanings of skulls from biological anthropology and cultural anthropology.
Let’s begin with the anatomy of a skull.
Skull composed of 22 visible bones (3 ear ossicles on each side are not counted). Other than the mandible (the lower jaw), these bones are tightly articulate at the suture line. As a person aged, the suture lines will fuse together, and thus keep bones in place. Skulls are widely studied by scholars, thus divided into four topical areas: bones, sinuses, landmarks and sutures. We are going to look at them one by one in brief:
Sutures
As mentioned above, it is the lines where the bones of the skull meet and fuse together in the later stage of one’s life. Some sutures would even completely obliterated in old age, which is definitely a feature to help determine age of deceased.
Sinuses
Sinuses refer to the pockets of air within sections of some of the cranial bones. The frontal sinus is an open area that lies above the upper boarder of the eye orbits, as well as the lower portion (towards nose) of the frontal bone. Maxillary sinuses are other larger sinuses in the upper jaw. Research has it that frontal sinuses in particular are unique enough for getting positive identification by comparing with antemortem (before death) radiographs.
Landmarks
These are the measuring reference points for measurement or description purposes.
Bones
Speaking about bones, I would like to focus on how anthropologist use skull to sex and determine ancestry from the anthroposcopic characteristics. First for sexing, including the overall size of the skull, there are 6 traits anthropologist would look for when sexing with the skull: mastoid process, nuchal crest, supra-orbital margin, supra-orbital ridge, and mental eminence.
- Mastoid Process: Male exhibits larger (and fatter) mastoid process when compares with females
- Overall size: Male skull is larger in size and more robust, and usually with more prominent and pronounced features
- Nuchal crest (or, the hook at the back of one’s head) : Male usually comes with a rugged nuchal area with inion hook, while female usually has a smoother nuchal area and the inion hook is absent.
- Supra-orbital margin (the margin of the upper eye socket): Males usually have more rounded and smooth margin, whereas female exhibits a sharper and pointy margin in comparison.
- Supra-orbital ridges: Male has a more pronounced ridge, where female has less pronounced or absent of ridges
- Mental eminence on the lower jaw: Male usually observed with a more squared chin, while female is usually observed with a more pointed one.
For ancestry estimation, anthroposcopic traits are the main way for ancestry classification. Yet, traits are categorized by gradation, and thus the ambiguities make ancestry as the most difficult attributes to be made.
These days, differentiations are no longer obvious as above. It mostly relied on the sense of touch when the osteologist or anthropologist feel and “communicate” with the bones. Also, anthropologists would never solely determine a biological profile component from one characteristic. Rather, they would gather as much info as possible from the skeleton in order to make the estimation more accurate.
References:
Byers, Steven N.. (2011). Introduction to Forensic Anthropology. 4th edition. Upper Saddle River: Prentice Hall, Chapter 7-8.