New endemic mammal species for Europe: Sciurus meridionalis (Rodentia, Sciuridae)

Combining genetic, morphological and geographical data, we re-evaluate Sciurus meridionalis, Lucifero 1907 as a tree squirrel species. The species, previously considered a subspecies of the Eurasian red squirrel, Sciurus vulgaris, is endemic to South Italy with a disjunct distribution with respect to S. vulgaris. The new species has a typical, monomorphic coat colour characterized by a white ventral fur and a very dark-brown to blackish fur on the back, sides and tail. Specimens of S. meridionalis have a larger hind foot length and weigh about 35% more than live-caught S. vulgaris from northern Italy. S. meridionalis is larger than S. vulgaris specimens from three other regions in Italy for mandible length, skull width and skull (condylobasal) length, and principal component scores indicate significant shape differences of specimens from the Calabria population (S. meridionalis) compared to all other specimens (S. vulgaris). These morphological differences are further supported by genetic evidence at three mitochondrial markers (D-loop, cytochrome b and the DNA barcoding region COI) using the widest molecular dataset ever assembled for Sciurus vulgaris and S. meridionalis. All the investigated markers revealed exclusive haplotypes for S. meridionalis well separated from those of S. vulgaris and previously published results based on nuclear markers further support our taxonomic hypothesis. We suggest Calabrian black squirrel as common name for this new taxon.