Caninae (whose members are known as canines () is the only living subfamily within

Canidae Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...

, alongside the extinct Borophaginae and Hesperocyoninae. They first appeared in North America, during the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

around 35 million years ago, subsequently spreading to Asia and elsewhere in the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

at the end of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, some 7 million to 8 million years ago.

Taxonomy and lineage

The genus '' Leptocyon'' (Greek: ''leptos'' slender + ''cyon'' dog) includes 11 species and was the first primitive canine. They were small and weighed around 2 kg. They first appeared in Sioux County, Nebraska in the Orellan era 34-32 million years ago, which was the beginning of the

. This was the same time as the appearance of the Borophaginae with whom they share features, indicating that these were two sister groups. Borophaginae skull and dentition were designed for a powerful killing bite compared with the ''Leptocyon'' which were designed for snatching small, fast-moving prey. The species ''L. delicatus'' is the smallest canid to have existed. At the close of their genus 9 million years ago one ''Leptocyon'' lineage resembled the modern fox. The various species of ''Leptocyon'' branched 11.9 Mya into Vulpini (foxes) and Canini (canines). 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. The first canine to arrive in Eurasia was the coyote-sized ''Canis cipio'', whose scant fossils were found in Spain. However, the assignment of ''C. cipio'' within the canines to the genus ''

Canis ''Canis'' is a genus of the Caninae which includes multiple extant taxon, extant species, such as Wolf, wolves, dogs, coyotes, and golden jackals. Species of this genus are distinguished by their moderate to large size, their massive, well-develo ...

'' or genus '' Eucyon'' is not clear.

Phylogenetic relationships

The results of allozyme and

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

analyses have previously suggested several

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

divisions:

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

analysis shows that the first three form

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s. The wolf-like canines and the South American canines together form the tribe Canini. Molecular data imply a North American origin of living Canidae some 10 Mya and an African origin of wolf-like canines (''Canis'', ''Cuon'', and ''Lycaon''), with the jackals being the most basal of this group. The South American clade is rooted by the maned wolf and bush dog, and the fox-like canines by the fennec fox and Blanford's fox. The gray fox and island fox are basal to the other clades; however, this topological difference is not strongly supported. The cladogram below is based on the phylogeny of Lindblad-Toh (2005) modified to incorporate recent findings on ''Canis'', ''Vulpes'', '' Lycalopex'' species, and '' Dusicyon''.

References

{{Taxonbar, from=Q2474088 Extant Miocene first appearances