It is a subspecies of "Canis lupus". They were regarded by Nowak as taxonomic synonyms for "Canis lupus". It is a valid taxonomic subspecies classified as "Canis lupus baileyi". The Alaskan wolves spread to become the northern wolves referred to as "Canis lupus arctos". For a list of wolf subspecies, see Subspecies of Canis lupus. The study recommended the recognition of "Canis lupus italicus". The Arabian wolf is small for "Canis lupus". It is regarded by Nowak as a taxonomic synonym of "Canis lupus furlongi". Wolves, dogs, and dingoes are all subspecies of "Canis lupus". A black wolf is a melanistic colour variant of the gray wolf ("Canis lupus"). He classified the domestic dog as "Canis familiaris", and the wolf as "Canis lupus". The nominate subspecies is the Eurasian wolf "Canis lupus lupus". The gray wolf ("Canis lupus") has wide phenotypic plasticity. The dingo ("Canis lupus dingo") breeds freely with other domestic dogs. The dingo ("Canis lupus dingo") refers to the dog found in Australia.