1. Taphonomy
Defined by Efremov (1940) as “the study of the accumulation and modification of osteological assemblages from a site formation perspective.”

2. Goals of Taphonomy Reconstruct paleoenvironments
Determine which factors cause the differential destruction or attrition of bone
Understand selective transport of remains
Discriminate human from nonhuman agents of bone modification

3. Forensic Anthropology and Taphonomy
Forensic Anthropology shares the last three of these goals, but are also interested in:
decomposition rates and patterns
disarticulation
dispersion of body parts
modification of soft tissue and bone
In order to show
time and circumstances of death
postmortem vs. antemortem/perimortem conditions
identifying factors

4. Forensic Taphonomy
Can therefore be described as the use of taphonomic models to
reconstruct postmortem interval
reconstruct conditions before and after deposition
discriminate the products of human behavior from those created by the earth’s biological, physical, chemical and geological subsystems

5. Autochthonous Allochtonous where death occurred
different from where death occurred

6. A Forensic Taphonomic Model
Four dimensions
objects
human remains
space
on the surface
within other environments (e.g. water)
buried
allocthonous vs. autochthonous
modification of objects
cultural dimension
cause and manner
investigator bias

7. Two major temporal concerns
perimortem interval
includes the timing of specific events such as trauma as they relate to the time of death
postmortem interval
ordinal (sequence of events)
interval (absolute time)
ratio (relative to some other temporal sequence)

8. Perimortem Interval
Estimating time of injury is difficult in the best cases
Must be able to determine conditions under which certain taphonomic conditions come into play
but these processes are not precise, so the boundry between life and death becomes blurred

9. Postmortem Interval Also imprecise
After death, the muscles of the body become flaccid
Within 1-3 hours the muscles become increasingly rigid and the joints freeze
rigor mortis
All muscles begin to stiffen simultaneously, but it is noticeable in smaller muscle groups first

10. Rigor mortis
Complete rigor takes hours to develop under ideal conditions
70-75 degrees Fahrenheit
The body remains stiff hours
Heavily impacted by temperature and other environmental conditions, body size, activity prior to death, etc.

12. Livor Mortis Also known as lividity
discoloration of the body after death due to gravitational settling of blood
Usually noticeable approximately 1 hour postmortem, apparent early often
Becomes fixed in about 8-10 hours
Visible until decomposition changes the color of the body

14. Algor Mortis
Normal cooling of a body which takes place as the body equilibrates with the external temperature
Occurs at an approximate rate of 1.5 degree F an hour
this is obviously dependant on external temperature

15. Decomposition In general, occurs in stages
after rigor passes, green discoloration of the skin become evident
generally begins on the abdomen about 24 hours after death
The body will begin to swell (bloat) due to production of gas by bacteria in the large intestine
may begin within 96 hours after death, sooner if warm or wet
As the body bloats, the outer layers of the skin begin to slip off the body, as will the hair and nails

16. Also during bloat body fluids may purge through the nose and mouth and other orifices.
At about the same time, the blood within vessels degenerates and darkens, giving the skin a marbled appearance

20. Order of Decomposition
Intestines, stomach, accessory digestive organs, heart, blood, circulatory system
air passages and lungs
kidneys and bladder
brain and nervous tissues
skeletal muscles
connective tissues