7 - FREQUENCIES OF SKELETAL PARTS

Summary

After death, vertebrate carcasses are often subjected to the same mechanical laws of transport by geologic agents as any other component of the sediment. Their specific gravity, which changes according to changing buoyancy, and the relation of mass to surface area specify the mechanical arrangement.

(J. Weigelt 1927/1989:160—161).

Introduction

One of the most obvious and visible properties of a faunal assemblage is the frequencies of each of the particular skeletal elements that make up the collection. A complete mammal skeleton, for example, always consists of two humeri, two scapulae, two mandibles, one skull, etc. From this model of relative frequencies of skeletal parts in an individual, one can predict what should be found in a fossil assemblage that contains, for instance, 10 skulls; here, 20 humeri, 20 scapulae, 20 mandibles, etc., should be found if taphonomic processes have not resulted in the removal of certain kinds of bones, and sampling and recovery processes have not failed to find certain skeletal parts. Analysis of skeletal part frequencies, or what are sometimes called skeletal part profiles, has, in the past 15 years, become a major part of taphonomic research. In fact, the references cited in this chapter show that there has been a major burst of publication on this topic in the late 1980s and early 1990s.