Resource and niche differentiation mechanisms by sympatric Early Pleistocene ungulates: the case study of Coste San Giacomo
Resource competition and niche partitioning among the exceptionally high number of sympatric ungulates
of the Early Pleistocene site of Coste San Giacomo (Central Italy) is here examined through the
study of their dietary proclivities and body size. The main aim of this study is to investigate the niche
differentiation mechanisms that let the fossil ungulates coexist in the same region. We also provide
information about the complementarity of two different methodologies that observe diet variation at a
different time scales (inner and outer mesowear) in the study of dental wear patterns of fossil ungulates.
Results from analyses of dental wear degree and body masses predictions show that a wide range of
feeding behaviours were adopted by the taxonomical groups (i.e., cervids, bovids and equids) in order to
avoid competition. Among larger ungulates diet ranges from strict browsing (Eucladoceros sp., Gazellospira
torticornis), to mixed feeding (Gallogoral meneghinii, Leptobos sp.) to pure grazing (Equus stenonis),
whereas smaller taxa are more selective feeders (Axis cf. lyra, Croizetoceros cf. ramosus) with only one
exception (Gazella borbonica). When taxa with the same feeding behaviour occurred in the same habitat,
competition was minimised by differences in body size.