Sunday, June 26, 2011

Faunal Taphonomy

This is a slightly updated version of a web page I made for Valeri Craigle of the Spencer S. Eccles Health Sciences Library at the University of Utah. Original funding was provided by a grant from the National Library of Medicine, Grant #1 G08 LM05684-01A1.

Valeri created a significant resource for Forensic Anthropology that was used by researchers, criminal investigators, and students around the world. Unfortunately, short-sighted administrators prevented site maintenance after expiration of the grant, and have not even supported it as a static resource on their server. I have added additional photographs, and text, but have tried to leave the page "dated."

I was personally honored to be associated with the project. I have also been involved with criminal investigations I can now identify (2013);


September 1998
Advisement to Judy Suchey, Orange County Forensic Anthropologist, taphonomy of scattered skeletal remains
in a rural setting. During that on-site study, discovery of a clandestine grave and subsequent
excavation of the grave site. Orange County Coroner Case # 98-0574OMU.

February 1999
Advisement to Judy Suchey, Principle Forensic Anthropologist. Burial site excavation of a
suspected homicide. Recovery and documentation of osteological, and material evidence
during excavation, and laboratory analysis. Orange County Coroner Case # 99-00133EY.

April 1999
Advisement to Judy Suchey, Principle Forensic Anthropologist. Site investigation following
discovery of a human skull in a suburban domestic setting. (Anaheim Police Department)

April 2000
Expert Witness Certification by the Supreme Court of the State of Tennessee. Knox
County Criminal Court Case No. 68318. Taphonomic analysis of human remains
from a homicide.

Faunal Taphonomy

One aspect of archaeological faunal analysis is determining the origins of recovered bone. The analysis of the processes which modify bone is called taphonomy, and is also of interest to forensic scientists as an aid to the investigation of homicides. Since 1989, Saddleback College students directed by Dr. Gary Hurd have studied the residue of deer predation by mountain lions. In the west, the major scavenger, or secondary predator, of the deer carcass is the coyote.

(The author (right) is assisting Duggin Wroe collecting DNA samples from a young male mountain lion. The animal was tagged and released).

There are several features of whole carcass changes that are worth noting. Forelimbs are generally the first anatomical unit to become disarticulated, followed by the hind limbs. the likelihood of removal is directly related to the degree of competition among scavengers at the carcass. There is a tendency towards lateralized bone consumption most easily observed in the bone loss from the ribs, and the lateral processes of the vertebrae.

Unlike the reports available for human carcasses, the deer skull is rarely relocated away from the primary kill site. The primary predator of the deer in the top photo was a mountain lion. The second animal was killed by an automobile. In that example, there was bone modification due to impact.

Trampling damage and tooth scaring on a deer scapula caused by coyote puppies. Puppies are weaned in the late spring-early summer. The adults return to their den with parts of carcasses for the puppies to teeth on, and wean. Tooth marks are limited to scoring. The foraging range for the coyotes will obviously vary depending on quality of the habitat. Note the polish on high spots from grasses. The primary predator is unknown.

Above is a slide showing trampling damage on a deer ulna. These marks were produced by predators moving the bone against stones. They lack parallel marks on the obverse of the bone found from tooth scoring, and are often rotated from a common origin.

Tooth scaring on deer bone; puncture with a radiating fracture (left: ulna), and compression (right: humerus).

Carrying damage to a deer metapoidal (cannon bone) caused by a coyote. These marks are diagnosed by parallel sets, spacing (appropriate to coyote dentition), and corresponding tooth mark sets on the obverse of the bone. These are particularly common on long bones, and sometimes show a "stepped" feature caused by parts of the limb snagging against brush.

Long bone splinters recovered from a coyote "bone yard" following a fuel rich wildfire. Notice that there is variation in the degree of burning which ranges from charred to calcined. Bone buried beneath as little as 4 cm of silt will be unburnt.

Gary S. Hurd graduated in 1976 with a Social Science Ph. D. degree from the University of California, Irvine. Following a ten year stint as a medical researcher in Psychiatry, he returned full time to archaeology. Currently, Dr. Hurd teaches anthropology courses at Saddleback College, and is Curator of Anthropology at the Orange County Natural History Association. He has been active in taphonomic research since 1989, and has also consulted with the Orange County Sheriff / Coroner's Office on bone modification, and evidence recovery related to suspected homicides.

(I was the Instructor of the Year, and given a Commendation of Excellence by the college Board of Trustees in 2001- the same year the anthropology department chair, Christen Brewer, canceled all my classes in revenge).

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