Chance and the taphonomy of the hominoid assemblage from the middle Miocene site at Paşalar, Turkey

A primary goal of taphonomy is to serve as a link between fossil assemblages and the original ecosystems from which they were derived. An important component of this endeavour is the estimation of bias or information loss in the fossil record. Previous approaches have focused on identifying abiotic and biotic sources of bias. Here we address how stochastic or random effects may have influenced the formation of the hominoid fossil collection and the total fossil hominoid assemblage from the middle Miocene site at Paşalar in Turkey. The fossil hominoid collection from Paşalar consists of over 700 isolated teeth of Griphopithecus (Hominoidea, Primates) that were derived from a total fossil hominoid assemblage representing a minimum of 35 individuals. We use computer simulations to test for stochastic effects in the fossil collection, and to develop a method (the Bilateral Equity Method) that can be used to estimate the completeness of any collection of isolated, antimeric elements. We also use computer simulations to determine whether stochastic effects could have influenced the composition of total fossil hominoid assemblage at Paşalar, and if so, to what extent. Results from this study indicate that stochastic effects, as an inherent component of abiotic and biotic taphonomic bias, played an important role in the formation of both the fossil hominoid collection and the total fossil hominoid assemblage at Paşalar.