Re-defining Canis etruscus (Canidae, Mammalia): a new look into the evolutionary history of Early Pleistocene dogs resulting from the outstanding fossil record from Pantalla (Italy)

An outstanding sample of Canis etruscus has been found within the faunal assemblage from the early Pleistocene site of Pantalla (Italy), which is referred to the early late Villafranchian. Canis etruscus appeared in Europe about 2 Ma ago. It is regarded as an important taxon for biochronology, as its first occurrence (the “wolf event”) has been used to define one of the Villafranchian faunal turnovers. The discovery of four crania from Pantalla prompted a revision of C. etruscus, in order to better describe its cranial morphology. Since early studies, the distinction between C. etruscus and the coeval C. arnensis has been based mainly on mandibular traits. For this reason, our study is aimed at highlighting differences in craniodental characters between the two species. Canis arnensis has been conventionally considered a jackal-like dog, while C. etruscus is regarded as a wolf-like dog. Consequently, we decided to use jackals for comparison, in addition to C. lupus. Although the jackal group has been traditionally considered as quite homogenous (different species are partially sympatric and similar in both size and ecology), recent genetic studies demonstrate that jackals are not monophyletic. Considering the model offered by extant species, our goal is to delineate the degree of intra- and interspecific variability among the basal forms of the genus Canis.