Dog from multiple grey wolf populations, with the dingo and New Guinea singing dog "breeds" having developed at a time when human populations were more isolated from each other. In the third edition of "Mammal Species of the World" published in 2005, the mammalogist listed under the wolf "Canis lupus" its wild subspecies, and proposed two additional subspecies: ""familiaris" Linneaus, 1758 [domestic dog]" and ""dingo" Meyer, 1793 [domestic dog]". Wozencraft included "hallstromi" - the New Guinea singing dog - as a taxonomic synonym for the dingo. Wozencraft referred to the mDNA study as one of the guides in forming his decision.
Dog anatomy study of dog skull shape compared to extant carnivorans proposed that "The greatest shape distances between dog breeds clearly surpass the maximum divergence between species in the Carnivora. Moreover, domestic dogs occupy a range of novel shapes outside the domain of wild carnivorans." The domestic dog compared to the wolf shows the greatest variation in the size and shape of the skull (Evans 1979) that range from 7 to 28 cm in length (McGreevy 2004). Wolves are dolichocephalic (long skulled) but not as extreme as some breeds of dogs such as greyhounds and Russian wolfhounds (McGreevy 2004). Canine brachycephaly (short-skulledness)