Animal bone fragments in a black bin liner. Reported to the police and the photo sent to Tim Thompson
Animal bone fragments

Introduction to Forensic Taphonomy

Forensic taphonomy is the study of what happens to a body between death and recovery. A large amount of forensic research focuses on trying to better understand taphonomic factors. Some of this research takes place in dedicated taphonomic research facilities, such as the famous Forensic Anthropology Center in Knoxville, Tennessee widely referred to as ‘The Body Farm’.

Anthropological methods will work best when applied to bones that are well preserved. Also, skeletons are easier to recover from the ground if they are complete and in good condition. Unfortunately, this is not always the case. There are a wide range of factors that affect the quality and quantity of bone that is recovered in forensic investigations. We call these taphonomic factors.

Skeleton in the ground that is in the process of being excavated Copyright David Petts

It is important to understand how these factors affect the body so that we can better interpret information about the body and the context of death and burial.

Intrinsic Factors

Some of the variation in how a body decomposes is to do with the person. This includes factors such as age-at-death, sex, and the presence of any pathology.

For example, as part of the natural ageing process, we lose bone mass with increasing age. This is why elderly people are more likely to sustain broken bones when they fall over. This low bone mass can also affect preservation after death and burial. The poorly mineralised bones are more porous and fragile and may decay more quickly.

A line drawing of an infant skeleton and the skeleton of an adult female. Both are laying on their sides and facing each other Line drawing of the skeletons of an infant and adult female (Copyright Durham University)

Infant bones may not be recovered as easily as adult bones. Again, their bones are less well mineralised, but when found they often survive quite well, even for thousands of years. The key problem with infant bones is their small size, which makes them easy to miss at excavation, or frequently mistaken for animals. The picture below shows an infant skeleton being uncovered from a Roman site (c2000 years old) in Britain. The bones have survived well but note the damage to the skeleton due to later disturbance of the grave.

An infant skeleton in situ in the soil at a Roman site. There is damage to the skeleton due to a whole that has cut through part of the lower half of it An infant skeleton from a Roman site

Pathological status is important. If someone has a condition that affects bone mass in any way then this will affect the survival of the bone in the ground. An example of this is the vertebrae below which show compression fractures (note that some vertebrae have thinner bodies than others) and thinning of the bone due to osteoporosis. Although you can’t tell from the photograph the bones are very light in weight which also indicates a loss of bone mass.

Vetrebrae with osteoporosis. Some of the vertebral bodies are compressed and show a loss of bone mass Copyright Durham University

Factors relating to the assailant

  • If a person has an open injury, when they are buried this can affect the speed of decomposition because the wound provides a means of entry for animals to attack the body.

  • If a body has been frozen then this will slow down decomposition (but not completely stop it). If the body then thaws out decomposition will speed up very rapidly.

  • If a body is wrapped tightly in plastic prior to burial or disposal, this will slow down decomposition and will hinder animal scavenging of the remains as well as the impact of plants, insects and other disturbance on the body.

  • If multiple bodies are buried within a single grave then this will have an impact on the decomposition process and will also make the recording and recovery of the skeletons more complicated (we’ll explore this further in Week 6).

  • Occasionally, bodies are deposited in very hard to reach areas, such as thrown down a well, or into a crevasse. Doing so not only serves to hide the body well, but it also complicates recovery of the remains.

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This article is from the free online course:

Forensic Archaeology and Anthropology

Durham University