PHYLOGENETIC TAPHONOMY: A STATISTICAL AND PHYLOGENETIC APPROACH FOR EXPLORING TAPHONOMIC PATTERNS IN THE FOSSIL RECORD USING CROCODYLIANS

摘要

Actualistic observations form the basis of many taphonomic studies in paleontology. However, surveys limited by environment or taxon may not be applicable far beyond the bounds of the initial observations. Even when multiple studies exploring the potential variety within a taphonomic process exist, quantitative methods for comparing these datasets in order to identify larger scale patterns have been understudied. This research uses modern bite marks collected from 21 of the 23 generally recognized species of extant Crocodylia to explore statistical and phylogenetic methods of synthesizing taphonomic datasets. Bite marks were identified, and specimens were then coded for presence or absence of different mark morphotypes. Attempts to find statistical correlation between trace types, marking animal vital statistics, and sample collection protocol were unsuccessful. Mapping bite mark character states on a eusuchian phylogeny successfully predicted the presence of known diagnostic, bisected marks in extinct taxa. Predictions for clades that may have created multiple subscores, striated marks, and extensive crushing were also generated. Inclusion of fossil bite marks which have been positively associated with extinct species allow this method to be projected beyond the crown group. The results of this study indicate that phylogenies can and should be further explored for use as predictive tools in a taphonomic framework.