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. The page was archived at:
https://archive.ph/TE1me


 

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);


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 See; Beier P, Barrett RH. The Cougar in the Santa Ana Mountain Range, California. Final Report, Orange County Cooperative Mountain Lion Study. University of California, Berkeley, CA, Management DoFaR; 1993 file:///C:/Users/Gary/AppData/Local/Temp/DicksonandBeier2002.pdf).


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.


Here is a list of our papers on taphonomy with student co-authors, and presenting information;

1996 "Raptor Prey Bone Accumulations from a Nest Area." G. S. Hurd, M. S. Pyatt. Southern California Academy of Science,

1996 "Deer Bone Accumulations from Mountain Lion Kills" Rick Travis  and G. S. Hurd. Southern California Academy of Science,

1998 "Carnivore Modification of Deer Bone" Steve McCormick,  G. S. Hurd. Society for Californian Archaeology.

1998 "Bone Modification and Deposition by Raptors" Mike Pyatt, Melissa Pryor, Gary Hurd.  Society for Californian Archaeology.

1998 "Rockshelter Deposition of Insect Remains By Fox and Mouse" Matt Ritter, Gary Hurd.  Society for Californian Archaeology.

1998 "Fish Bone Deposition by Coyote" Karl Allwerdt, Gary S. Hurd. Society for Californian Archaeology.

1998 "Primary and Secondary Predation Patterns of Avian Bone," Ken Reddell, G. S. Hurd, Society for Californian Archaeology).

FORENSIC CASES

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.

Since this case is so old, I think I can add a bit:
A Rancho Mission Viejo cowboy (legit - horse, hat, the whole deal) found a pelvis, a femur, and some odds and ends.

The pelvis and femur were human from an adult male. I pointed the deputies to the coyote tooth marks from adults when they ravaged the body. And then the ones from the puppies teething and weaning.

The deputies were losing interest. I could imagine them thinking "Is this NatGeo, or a murder investigation?"

Then I pointed to some other marks, and said, "That is from a 38 cal bullet." Now they were interested. And when I pointed to some other marks and said, "That mark is from a 9mm hollow point."

And they were thrilled.

Back to the puppies- they told us that the body was dumped in late June or early July.

We found the bullet fragments when we excavated the burial site.


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.

My best professional complement ever was related to this forensic taphonomy contract.

I received a phone call in April 2000 from a woman who was a Public Defender in Knoxville Tennessee. She asked if I was the Doctor Hurd who was a forensic bone expert, and if I would work on a defense team.

I replied Yes, I would work for investigators, or defense as the scientific results from me would be the same either way. But, I added, the best forensic taphonomist in the WORLD was William Bass https://en.wikipedia.org/wiki/William_M._Bass , and he was “just down the street” from her.

She replied that Prof. Bass was already involved as the Prosecution’s expert witness.

I said, “Then you are screwed. I read Bass. He does not read me. If I disagreed with him on a technical issue, I would assume I am wrong.”

She laughed and continued, “The prosecution hired Dr. Bass only to identify the sex of the victim.”

I was confused, and mentioned that that was crazy. “A Junior High kid could do that after they had “health” class.” And her answer was that the prosecution had hired Bass to keep him from helping her client’s defense.

“Well then I on the job, and I expect we will win.”

She laughed some more and said, “It was Prof. Bass that gave me your name.”



December 2016

Expert analyst and physical anthropology defense consultant. Matthew Nardi, Wailuku HI
96793, defense counsel for Steven Capobianco.  Trial concluded Dec. 2016.

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