Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Sociology and Anthropology

Committee Chair(s)

David A. Byers


David A. Byers


Jacob Freeman


Patricia Lambert


In archaeology, the study of animal remains helps researchers understand what animals past hunters sought to prey upon and what decisions they made related to field butchery. Archaeological excavations in sites of the Northern Great Plains and the Snake River Plain have shown that a disproportional amount of bison limb bones occur relative to other bones in the body. Limb bones contain marrow, and to break these open ancient butchers would use hammer stones and rock anvils. Such processing behaviors often leave impact scars, and these often vary in frequency from one part of the skeleton to the next.

My research explores whether impact frequencies are more closely tied to marrow utility or bone resiliency, both of which vary across the bison skeleton. Marrow contains a high amount of fat and in periods of food scarcity, fat-rich foods become highly valuable. At the same time, resiliency to fragmentation varies across the bison skeleton as well. Subsequently, these relationships give rise to an interesting and important question. Specifically, are impact scar frequencies better explained as a response to bone resiliency or marrow nutritional utility.

My thesis addresses this question through an experiment in which 266 fresh bison bones were broken using a four-pound steel ball bearing released by an electromagnet drop machine. Each specimen in my sample was subjected to repeated drops until they split open, allowing access to their marrow cavities. I kept count of how many strikes were needed to break open each bone. The results show that the limb bones with the highest amount of marrow were also the easiest to break open, which mirrors the frequency of bones with impact scars in the archaeological record. In contrast the bones most difficult to open also produced the least marrow. Therefore, impact scars seem to best reflect the processing effort past hunters expended to obtain their fatty nutrients.



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Anthropology Commons