dead-men-talking:
fuckyeahforensics:
Learning from Skeletons
Skull
Look for the sagittal suture – the squiggly line that runs the length of the skull – and note whether is it’s completely fused. If it is, the remains are likely to be of someone older than 35. Look for a second line at the front of the skull — the coronal suture – which fully fuses by age 40.
Teeth
Study the teeth. If they’re worn down it could be a sign of a poor diet. If they’re well-maintained and/or have good dental work such as fillings, they were able to afford proper dental care—another clue as to the identity of your skeleton. Consult a scientist who specializes in teeth, known as an odontologist. They can determine how old a person was at death, what kind of health they were in and what kind of diet they had.
Sternum
Examine where the ribs join the sternum. This is also a good indicator of age. A forensic anthropologist will compare it against a database of standard markers and it is often more accurate as it is not a weight-bearing bone and remains unaffected by childbirth.
Pelvis
Look for the pubic symphysis, which is the joint located in the pelvis. The older the person at death, the more pitted and craggy these bones will be. Forensic anthropologists will compare this against a database of standard markers to learn the age of the skeleton. Check if there are any soft marks on the cartilage which are left by childbirth as the bones soften to allow easier birth.
To identify gender, assess the pelvis shape; men have a narrow, deep pelvis and women a wider, shallower pelvis, better-suited to carrying a baby. For a quick identification in the field, a forensic anthropologist will find the notch in the fan-shaped bone of the pelvis and stick their thumb into it. If there’s room to wiggle the thumb, then it’s a female; if it’s a tight fit, it’s the skeleton of a man
Wrist
Examine the wrists, as bones often hold clues to the primary work of the decedent. Bony ridges form where the muscles were attached and pulled over the years. A forensic anthropologist might find a bony ridge on the wrist and decide the dead person may have been someone who used their hands for a living, such as a chef or seamstress.
DNA
DNA samples may be taken from any existing hair tissue. As well as positively identifying someone, it can also identify a person’s race or tribal origins.
Bugs
When the skeleton is first discovered, take samples from around the remains including any bugs you come across. Insects such as blowflies have a very distinct lifecycle and often plant their eggs on newly deceased bodies. By identifying the stage of the lifecycle, a near-exact time of death can be established. This science is known as forensic entomology.
OK, got a bit to add to this:
- Cranial sutures are basically useless for age estimation. Generally speaking, yeah, more open means younger, and more closed means older, but this is more often determined by genetics.
- Teeth wear (attrition) also varies immensely by population. It’s very useful if you know where and when the person came from, and what diet they lived on, but these charts are not universal. A 24-year-old from ancient Egypt will have much more tooth wear than a 24-year-old from post-industrial England. Softer diet, less sand, etc. (I speak from experience in those two populations.) A lot of standards commonly referred to in archaeology are based on Native American populations.
- I’ve heard about using rib ends and longbones for age and sex estimation, but I haven’t followed up on it! The most widely accepted methods look at the pelvies, but forensic anthropologists are always looking for more precise methods pertaining to modern populations. (I’m looking forward to going back to school and learning this stuff!)
Reblogging for the comments, but I’d like to add even more!
With the Pelvis, we do not determine gender. We determine biological sex, which is not the same as gender. Also, while the pelvis is the best for determining the sex of an individual other skeletal features, such as those on the skull, should be taken into consideration when available. The original poster also mentioned signs of childbirth, all of which (including pitting) are not very reliable at all.
Rib ends can be useful for aging if available. Most of the time they are too badly damaged during the taphonomic process to use, and it is a good idea to compare your aging from more reliable areas (such as epiphyseal fusion, dental eruption, and pubic symphysis, NOT cranial suture closure which is, for the most part, no longer used). Also, while they may not be affected by childbirth, they are affected by upper respiratory infections (such as TB) which can alter their appearance and affect the age calculated from them.
As for the section on the wrists. Muscolo-Skeletal-Markers (MSMs), or Entheseal changes as they are now more commonly referred to as, are not indicators of profession or what a person was doing for a living in the past. There are multiple factors affecting the production of bone in specific areas of the body, and while on a large scale (say for instance a large population study), seeing marked difference in location of entheseal changes on separate groups can suggest a division of labour (Havelková et al 2011). For a better understanding of entheseal changes I would highly recommend: Villotte, S. and Knüsel, C. J. (2013), Understanding Entheseal Changes: Definition and Life Course Changes. Int. J. Osteoarchaeol., 23: 135–146
Ancestry is what is being determined from a skeleton, not race. (Although this may not be the case in forensics cases.)
Bugs: Paleoparasitology is also a thing.
Teeth, I completely agree with dead-men-talking. Wear cannot be used to age an individual with a processed diet.
