Naticid gastropod and octopodid cephalopod predatory traces: evidence of drill holes on the leucosid crab Ristoria pliocaenica (Ristori, 1891), from the Pliocene of the “La Serra” quarry (Tuscany, Italy)

Garassino et al. (2012) reported on a rich community of decapod crustaceans including axiideans, gebiideans, anomurans, and brachyurans from the Zanclean (Early Pliocene) of the “La Serra” quarry near San Miniato (Pisa, Tuscany, central Italy). In this decapod-rich assemblage some carapaces of the common pebble crab Ristoria pliocaenica (Ristori, 1891) (Leucosiidae Samouelle, 1819) are drilled in characteristic ways, due to the predatory activity of individuals belonging to two different taxa of marine clades, possibly naticids (Gastropoda, Naticoidea), and to octopodids (Cephalopoda, Octopoda). This is the first report of direct evidence of predation by cephalopods on crabs in the fossil record.