Who ate the small herbivores of the Wezmeh Cave? Taphonomic study of a Late Pleistocene/Holocene macrofauna
Résumé
The Wezmeh cave, located in the Zagros mountains in western Iran, has yielded thousands of faunal remains dating from the Late Pleistocene and Holocene. This cave is one of the few major sites which document the biodiversity and palaeoecology of large mammals at that time. A large assemblage of over ten species of carnivores (among which the most important are, in order of importance: red fox, spotted hyena, brown bear, wolf) and a rich assemblage of ungulates were discovered alongside a few human remains, including one premolar attributed to Homo neanderthalensis. Looting activities disturbed the stratigraphy of the site before its discovery, making it difficult to interpret the origin of the accumulations, whether anthropogenic or animal. Previous studies put forward the hypothesis that this accumulation was mainly due to carnivores. The exhaustive taphonomic study of over 2,000 herbivore remains has clarified the role played by the different carnivores, and brought to light the role of humans, at least partially. The diverse herbivore assemblage is mostly composed of ovi-caprines and to a lesser extent of suids. Carnivores of small to medium size are mainly responsible for the accumulation and modification of these remains. Nonetheless, a few cut marks and burnt bones indicate that humans also played a role in the accumulation. Traces of modification by carnivores and humans are mainly present on ovi-caprine remains, but also on other taxa including suids. The exploitation and consumption of suids by humans or carnivores has rarely been documented in the fossil record and attests to diverse subsistence strategies. However, most of the bone surfaces do not present any traces, suggesting that natural processes like trapping or sheltering played an important role in this accumulation. For wild ovi-caprines this hypothesis is strongly supported by eco-ethological data, allowing us to put forward the hypothesis of in situ death for ovi-caprines, and generally the use of the cave as a shelter for some herbivores. This study highlights the complexity of ovi-caprine-rich assemblages, resulting from multi-agent accumulation processes.