Foresnic Taphonomy

taphonomy

the study of what happens to the remains of an animal from the time of death to the time of discovery

• origins in paleotology (fossilization)

forensic taphonomy

the processes (human or natural) affecting the final deposition of the body preceding, during, and following death

• postmortem interval (PMI)

• original position and orientation of the body

• human variation

what is initial postmortem tissue changes

1. algor mortis

2. liver mortis

3. rigor mortis

algor mortis

• cooling of the body after death

  • living body temperature (98.6F) (Ambient temperature)

  • rate of about 1.5F per hour for first 12 hours

livor mortis

• characteristic coloration of skin caused by blood pooling in body after death

  • unfixed

  • fixed

rigor mortis

• stiffening of muscles after death

  • 2-6 hours to 24-36 hours

autolysis

• self digestion

• destruction of cells through action of its own enzymes

putrefaction

microbial deterioration of tissues caused by proliferation of bacterial assoicated with digestive system

• bloating

mummification

preservation of remains by desiccation

• low humidity

• arid area (hot or cold)

saponification

conversion of fatty tissue to adiopocere

• moisture required (can be from body)

• “grave wax)

differential decomposition

different stages of decomposition across differernet body parts

• trauma

• exposure

• prior bacterial infection

skeletonization in decomposition

completion of soft tissue decomposition, where only hard tissues remain

what are the general stages of decomposition

• fresh

• bloat

• active decay

• advanced

• skeletal

variables that affect decomposition

• temperature

• humidity

• water near or around the body

• clothing

skeletonization in postmortem skeletal changes

includes subsequent breakdown of skeletal elements

• bone staining and color changes

  • soil

  • organic

  • metal

weathering

postmortem modificationproecess of hard tissues as a response to natural agents in their environment

• bleaching

• longitudinal cracking

• flaking

scavenging

consumption and associated modification of remains by other animals

• succession

succession

scavening by different species at different stages of decomposition

what are some scavening things

• insects

• carnivores

• omnivores

• rodents

• vultures

what is the purpose of body movement and disarticulation

understanding expected body positioning during decomposition

• altering: scavengers, water, human, etc

postmortem interval (PMI)

time since death

• narrows missing persons list

• provides evidence for circumstances of death

• postmortem changes → early> later

accumulated degree days (ADD)

the sum of the average daily temperature for given number of days

• used to esitmate PMI

who uses accumulated degree days (ADD) and why

• forensic entomology

  • insect life stages

• forensic anthropology

  • total body scores