Hemisyntrachelus cortesii (Cetacea, Delphinidae) from Pliocene sediments of Campore Quarry (Salsomaggiore Terme, Italy)

Two new finds of Hemisyntrachelus cortesii (Cetacea, Delphinidae) from Pliocene clays at the Campore quarry near Salsomaggiore Terme (Italy) are recorded. The two specimens are described and comparisons among the fossil genus Hemisyntrachelus (recently re-evaluated by the author) and Tursiops are made. From a phylogenetic point of view, it is possible that Hemisyntrachelus and Tursiops are less specialized genera and that they are the sister groups respectively of the Globicephalinae and Delphininae subfamilies. Hemisyntrachelus, with its larger size and smaller number of teeth than Tursiops, was probably a generalist predator like the extant Pseudorca and perhaps the contemporary Orcinus citoniensis. Discoveries of Hemisyntrachelus are relatively common in the peri-Adriatic area but rare in Tuscany. This distribution indicates a possible provincialism in the Pliocene Mediterranean cetacean populations like that of today.