An actualistic and phylogenetic approach to identifying and interpreting crocodylian bite marks

摘要: Bite marks provide direct evidence of trophic interactions, feeding behavior, and inter- or intraspecific conflict in the fossil record. However, their utility as a source taphonomic paleoecologic data requires differentiation from traces left by other processes. Since 19th century, taphonomists have often relied on actualistic observations modern bite behaviors order to identify diagnostic patterns. A recent increase interest research has resulted large body work describing patterns many different clades. Most been focused mammalian taxa, but smaller number non-mammalian groups, including crocodylians, also drawn interest. Crocodylians are agents who consume modify bones, depositing them active depositional systems which they live. crocodylian limited forensic case studies surveys two taxa: Crocodylus niloticus porosus . Both utilized captive animals, exhibit atypical morphologies that may bias ensuing mark datasets. In address this issue, 2D morphometric analysis Alligator mississippiensis crania wild specimens was performed. principal component canonical variates revealed some statistically significant differences between while crossvalidation had mixed resuts. An ANCOVA test covariance centroid size origin against shape (principal scores) effects ontogeny introduced stronger signal than captivity. This implies using crocodylians fine scale analyses should be avoided, suitable for gross research, such analyses. To explore greater depth, survey A. types samples taken individual feedings were discussed light vital statistics collection protocols. group classified location orientation bone type. The results compared pre-existing datasets with regards potentially traits: bisected marks, hook scores, lack furrows. Bisected found rates similar those seen C. , scoring breakage higher. These present higher reported Furrows identified, rare. Finally, 21 23 generally recognized species extant performed better characterize across Crocodylia methods synthesizing then coded presence absence subscores. Attempts find…