Forensic Anthropology
Skeletal Anatomy(300 bones born-206 as an adult)
Bones tell us a lot about a person:
How a person lived
Illnesses-healed fx,osteoporosis,polio,curvature of spine
Lf. vs rt. handed
Clues to occupation
Age of person at time of death
Sex of person
Race
Height
Distinguish between human and animal
Manner of death-homicide,suicide,natural, accidental or unknown
How many individuals are represented
What was the SEX?
Male skeleton
- Man’s bone weigh ~12 lbs
- Pelvic bone is narrow
- Thicker skull, heavier and bigger
- Tend to have a bony supraorbital ridge
- Low slanted forehead
- Smooth upper eye rim
- Subpubic angle is less than 90 degrees
- Prominent nuchal crest-nape of neck/skull
- Thicker and longer leg and arm bones
- Male bones grow until 20-21 years old-
- Parkman’s jaw=prominent, jutting jaw, more angulated
Female skeleton
- Women’s bones weigh~10lbs
- Skull is thinner and not as heavy
- Rounded forehead
- Sharpened around supraorbital ridge
- Pelvis is wider-to accommodate child birth
- Subpubic angle is more than 90 degrees
- Pubic bones separate to allow additional room for the baby’s head and will leave a small indention/depression on the bones after the delivery of the 2nd child
What was the persons RACE?
- Africans and descendants -smooth elongated skull with wide broad nasal bone; distance between orbits is wide and; the bone between the bottom of the nose and the upper teeth projects forward
- Europeans-Caucasoid- rough and elongate skull;narrow and long nasal bones;distance between the orbits is narrow;projecting chins
- Australian aborigines and Pacific Islanders have a rounded, receding jaw.
- People of Hawaiian descent have a distinctive-shaped jaw. called rocker jaw-(when the mandible is placed on a table and gently tapped it will rock like a rocking chair b/c rounded jaw.
- Native Indians-flat cheek and nasal bones,rounded skull,b/c they practiced using cradleboards to carry babies,the board molded and flattened the head.
- Puerto Ricans-put tight crocheted caps on the infants to protect them from bad influences and that shapes the head
Because of mixed racial heritage it is more difficult now-depend on computers
Pencil test is done in the field to give police quick head start
Pencil test 1. attempts to touch one end of the pencil to
chin while touching the other end to the
nasal opening. If the pencil lies flat and
touches both points at the same time it
caucasoid. If it does not lie flat because of
the mouth section, it is prob. Africanoid
b/c of the way the teeth section protrude.
Pencil test 2. Nasal tilt-that little bit of bone at the base
of the nose between the nostril. by
running thepencil gently up into the
nasal opening, the pencil will be stopped
from entering the nasal opening b/c of
the tiny ridge there. If it is Africanoid, the
pencil will enter the nasal opening easily.
Pencil test 3. by laying the skull face up in the palm-the
pencil can be balanced across the nasal
opening. If a finger can be slid between
cheekbone and pencil without knocking
pencil off-caucasoid. Difficult to do on
asian b/c face is flatter rather than
pointy.
What was the HEIGHT?
No prob.when skeleton is intact. but with dismemberment
Mathematical formula by Dr.Mildred Trotter
Application mainly used in disasters-planes and Twin towers
Measured on osteometric board:
Length of femur x 2.38 + 61.41cm = height
Length of femur x 2.52 + 78.62 cm =height
Length of fibula x 2.68 + 71.78 cm = height
Convert to inches-feet
Femur of female 473mm. approx 68 inches tall or 5’8”
47.3cm x 2.38=112.574 add 61.41cm = 173.98cm divide by 2.54cm = 68 inches= 5’8” .
Age at time of death
based on how skeletal is formed- bones do not grow all in one piece. epipysis form separately from the diapnysis and fuse together and become hard bone is ossification. there are 450 centers of ossification that fuse. You can actually see how the bones fuse by holding the bones up to a light;if there is a slight glow throught the bones then they haven’t fused yet. if not light then they are fused. Table when each bone fuses in the body-
Contributed by E.Ogle 09/07
elbow 14
hands and feet15
ankle16
femur17
knee18
wrist19
shoulder20
crest of illium21
clavicle28
Contributed by E.Ogle 09/07
Sutures in skull form at different ages-sagittal suture by 35 and the coronal by 40.
Cut a small wafer of long bone and count the circles formed around the canal. formula for that also
Aging process
Osteoporosis-leaves the bones thinner, porous and susceptible to fx. by 55 lost 30% bone
Examine teeth-later on
What the person left handed or right handed?
Ball and socket joint is affect-with regular use the socket becomes beveled and a slight grove forms.
Lefty will have more beveling in the left shoulder socket
The dominant arm will be a few millimeters longer to compensate for the more work it does.
Occupation?
With over usage, bone and processes accommodate for over usage of muscle in that area. they will be more prominent. Waitress-left deltoid
High heels and cowboys strong calf muscles-
ridges in tibia
Manner of death?
Blows to head-bullet holes-force and angle of blows
Most cases the cause of death is apparent and gruesome.
Falling down stairs-evidence to support it
Autopsy is critical. body tissue & fluids:sampled,analyzed
Depressed fx-moving object caused the blow
Broken bones heal in a few months.New bone shows shiny rounded edges & xray reveals fine line where fx was. Dead bones don’t grow nor heal!
Knife-parallel cuts marks,shape of the edge of blade on bone
Gnawing-markings of rodent
Mower-destroy the bone
Mattock/axe & cut off in car door-clean cut
Circular saw-curved lines
Saber saw –regular straight cuts
Handsaw-irregular straight cuts
Serrated knives-scalloped-edged cut
Dull objects- U shaped depression
Sharp objects make a V shaped notch
Bones burn but not all the way-
body lying face up-smoke inhalation
body lying face down-dead prior to fire
Strangled-bone in throat will be fx
Poison-extracted from bone years later
Contributed by E.Ogle 09/07