Taxonomy of Dogs

In 1758, the taxonomist Linnaeus published in his Systema Naturae the classification of species. Canis is a Latin word meaning dog, and under this genus he listed the dog-like carnivores including domestic dogs, wolves, and jackals. He classified the domestic dog as Canis familiaris (Linnaeus, 1758) and on the next page as a separate species he classified the wolf as Canis lupus (Linnaeus, 1758). In 1926, the International Commission on Zoological Nomenclature (ICZN) ruled in Opinion 91 that the domestic dog Canis familiaris (Linnaeus, 1758) be placed on its official list. In 1957, the ICZN ruled in Opinion 451 that Canis dingo (Meyer, 1793) was the name to be used for the dingo and that this be placed on its official list. These are the scientific names for the dog and dingo that appear on the Official Lists and Indexes of Names in Zoology of the ICZN.

In 1978, a review to reduce the number species listed under genus Canis proposed that "Canis dingo is now generally regarded as a distinctive feral domestic dog. Canis familiaris is used for domestic dogs, although taxonomically it should probably be synonymous with Canis lupus." In 1982, the first edition of Mammal Species of the World included a note under Canis lupus with the comment: "Probably ancestor of and conspecific with the domestic dog, familiaris. Canis familiaris has page priority over Canis lupus, but both were published simultaneously in Linnaeus (1758), and Canis lupus has been universally used for this species". In the same year, an application was made to the ICZN to reclassify the dingo to Canis lupus dingo because it was proposed that the wolf (Canis lupus) was the ancestor of dogs and dingoes, however the application was rejected.

In 2003, the ICZN ruled in its Opinion 2027 that the "name of a wild species...is not invalid by virtue of being predated by the name based on a domestic form." Additionally, the ICZN placed the taxon Canis lupus as a conserved name on the official list under this opinion. In the third edition of Mammal Species of the World published in 2005, the mammalogist W. Christopher Wozencraft listed under the wolf Canis lupus what he proposed to be two subspecies: "familiaris Linneaus, 1758 [domestic dog]" and "dingo Meyer, 1793 [domestic dog]", with the comment "Includes the domestic dog as a subspecies, with the dingo provisionally separate – artificial variants created by domestication and selective breeding. Although this may stretch the subspecies concept, it retains the correct allocation of synonyms." Although the earliest use of the name "dingo" was Canis familiaris dingo (Blumenbach, 1780), Wozencraft attributed it to Meyer from 1793 without comment.

This classification by Wozencraft is hotly debated by zoologists. Mathew Crowther, Stephen Jackson and Colin Groves disagree with Wozencraft and argue that based on ICZN Opinion 2027, the implication is that a domestic animal cannot be a subspecies. Crowther, Juliet Clutton-Brock and others argue that because the dingo differs from wolves by behavior, morphology, and that the dingo and dog do not fall genetically within any extant wolf clade, that the dingo should be considered the distinct taxon Canis dingo. Jackson and Groves regard the dog Canis familiaris as a taxonomic synonym for the wolf Canis lupus with them both equally ranked at the species level. They also disagree with Crowther, based on the overlap between dogs and dingoes in their morphology, in their ability to easily hybridize with each other, and that they show the signs of domestication by both having a cranium of smaller capacity than their progenitor, the wolf. Given that Canis familiaris (Linnaeus, 1758) has date priority over Canis dingo (Meyer, 1793), they regard the dingo as a junior taxonomic synonym for the dog Canis familiaris. Gheorghe Benga and others support the dingo as a subspecies of the dog from the earlier Canis familiaris dingo (Blumenbach, 1780). Xiaoming Wang and Richard H. Tedford proposed that the dog should be classified as Canis lupus familiaris under the Biological Species Concept and Canis familiaris under the Evolutionary Species Concept.