Hic locus est ubi mortui viveuntes docent. This is the place where the dead teach the living.
3 FORENSIC ANTHROPOLOGY Forensic Anthropology combines the disciplines of anthropology and osteology; the study of bones. A forensic anthropologist will frequently work with odontologists, pathologists and investigators to make determinations about skeletal remains.
The Requirements A forensic anthropologist provides basic identification of skeletonized or badly decomposed remains. Once an object is identified as a bone, the scientist may be able to determine : Human vs. Non-human Age Gender Race Height
5 The Process First, the forensic anthropologist must determine if the remains are bones. Wood fragments, stones, pottery pieces or plastics are often mistaken for bones.
6 The First Determination - Are the bones human? Once the remains are verified as bone, the examiner must determine if the bones are human. Although, many human and non human bones look similar, there are a few very distinct differences.
7 The Skull The skull is very different between humans and non-humans. The eye orbits are located at the front in humans, on the side for non- humans. The mandible is U-shaped in humans and V-shaped in non-humans. Humans have a chin. Humans have a larger brain cavity.
9 Bones of the Body The upper limbs are less robust in a human. The human pelvis is wide, short and bowl-shaped. A non-human pelvis is long, narrow and blade-shaped. The arm and leg bones in humans are separate while in non-humans they are often fused.
11 Age Determination – The Next Step At birth the human body has approximately 350 bones. Many of these bones fuse and the adult human body has 206 bones. The number of bones found at the scene may help with an age range determination.
12 Age* Determination – The Next Step Most accurate estimations use: Teeth Epiphyses or growth plates Sutures: Cranial and Basilar There are three major cranial sutures that appear as distinct lines in youth and gradually close from the inside out. *Investigators always use an age range because of the variation in people and how they age.The investigator does not want to eliminate any possibilities for identification.
13 Age Determination- Teeth Age Determination- Teeth The first set of teeth erupt between 6 months and 3 years. There are 22 “baby” teeth. Between the ages of 6 years and 21 years, permanent teeth erupt. There are 32 permanent teeth. The investigator will have to determine which set of teeth are present in the skull.
14 Age Determination - Epiphysis An epiphysis is the growth plate area at the end of the long bone. These areas close or fuse at different ages. For females, fusion is complete between 18- 20 years. For males, fusion is complete between 17- 21 years.
15 An Infant or Fetal Skull An infant skull has spaces, or soft spots, between the bone plates. Sutures form where these bones fuse together.
Age Determination – Cranial Sutures There are three major cranial sutures that appear as distinct lines in youth and gradually close from the inside out.
17 Age Determination - Cranial Sutures Sagittal suture completely closed Males—26 or older Female—29 or older Sagittal suture is complete open Male—less than 32 Female—less than 35 Complete closure of all three major sutures Male—over 35 Female—over 50 Sagittal suture LambodialCoronal
Age Determination – Basilar Suture The basilar suture is located in the roof of the mouth. It closes in females as young as 14 and in males as young as 16. If the suture is open, the individual is generally considered 18 or younger.
19 The Next Step in the Process is Gender Determination The most important bone needed for gender determination is the pelvis.
Gender Differences in Bones The pelvis of the female is wider. Males have a narrow subpubic angle (A) and a narrow pubic bone body (B).
22 Gender Differences in Bones Gender Differences in Bones The ribcage and shoulders of males are generally wider and larger than that of females. In addition, about one person in twenty has an extra rib. This is more common in males than in females.
23 Male vs Female Skull The female skull is usually more rounded with a less pronounced forehead. Males have more pronounced upper eye orbit and upper cheek bone (zygomatic process). Males have a more squared or U-shaped lower jaw. Females have more rounded or V-shaped lower jaws (mandibles).
Gender Differences in Bones Although occurring less frequently, in males the index, or first, finger is usually shorter than the third finger. In females, the first finger is longer than the third finger. Is this a male or female hand according to the above rule?
Determination of Race Race is difficult to determine from most skeletal remains, especially since there are no pure races. However, an experienced forensic anthropologist can generally place skulls into one of three historic groups: Caucasoids – European, Middle Eastern and East Indian Descent Negroids – African, Aborigine and Melanesian descent Mongoloids – Asian, Native American and Polynesian descent
26 Race Characteristics Caucasoids—have a long, narrow nasal aperture, a triangular palate, oval orbits, narrow zygomatic arches and narrow mandibles. Negroids—have a wide nasal aperture, a rectangular palate, square orbits, and more pronounced zygomatic arches. The long bones are longer, have less curvature and greater density. Mongoloids—have a more rounded nasal aperture, a parabolic palate, rounded orbits, wide zygomatic arches and more pointed mandibles.
Racial Differences What differences do you notice between these three skulls? Could you tell each race?
Last Determination - Human Stature Height of a person can be calculated by using the length of certain bones, including the femur, tibia, humerus, and/or radius. Below are the general formulas (in cm) for both male and female. There are more specific charts if the race of the individual is known. MaleFemale femur x 2.23 + 69.08femur x 2.31 +61.41 tibia x 2.39 + 81.68tibia x 2.53 + 72.57 humerus x 2.97 + 73.57humerus x 3.14 + 64.97 radius x 3.65 + 80.40radius x 3.87 + 76.50
29 Facial Restoration After determining the sex, age, and race of an individual, facial features can be built upon a skull to assist in identification. Markers are used to make tissue depths at various points on the skull. Clay is used to build around these markers and facial features are molded.
30 Steps in Facial Reconstruction With a skull: Establish age, sex and race Plot landmarks for tissue thickness Plot origin and insertion points for muscles Plot landmarks for facial features Select a dataset and mount markers for tissue thickness Mount the eyes Model muscles on skull Add fatty tissue around eyes and lacrimal glands Add eyelids Add the nose Add the parotid gland Add the ears Cover all with layers of skin Detail the face
Anthropologist at Work This anthropologist is hard at work dusting away material from these imbedded bones. Picture taken at Chicago’s Museum of Natural History
Animal Facial Restoration Determining what T Rex looked like using the bone formation. From this: To this:
Animal Structure and Function Beaver jaw with the end results seen on the log.
Other Bone Identification Forensic experts may be called upon to determine the life and death of humans and animals in unique circumstances, including: –Mass Murder (Oklahoma bombing, plane crashes, World Trade) –Earlier man (mummies, Iceman, Lindow man) –Historical Significance (Holocaust, uncertain death of famous people) –Prehistoric Animals (Dinosaurs)