[7] †Hesperocyoninae †Borophaginae Caninae The genus Leptocyon (Greek: leptos slender + cyon dog) includes 11 species and was the first primitive canine.

[1]: 174–175 The canines spent two-thirds of their history in North America, before dispersing 7 million years ago into Asia, Europe, and Africa.

One of the characteristics that distinguished them from the Borophaginae and Hesperocyoninae was their possession of less weight in their limbs and more length in their legs, which may have aided their dispersion.

[6]: 143–144 The results of allozyme and chromosome analyses have previously suggested several phylogenetic divisions: DNA analysis shows that the first three form monophyletic clades.

[10] The cladogram below is based on the phylogeny of Lindblad-Toh (2005)[10] modified to incorporate recent findings on Canis,[11] Vulpes,[12] Lycalopex species,[13] and Dusicyon.