subfamilies
In biological classification
In biology
Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, ...
found within the canid
Canidae (; from Latin, ''canis'', "dog") is a biological family
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy; it is classified between order (biology), order and genus. A family ...
family. The other two canid subfamilies are the extinct Borophaginae
The extinct Borophaginae form one of three subfamilies found within the canid
Canidae (; from Latin, ''canis'', "dog") is a biological family of dog-like carnivora
Carnivora is an order of placental mammals that have specialized in prim ...
and Hesperocyoninae
The extinct Hesperocyoninae are one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Borophaginae and extant Caninae.
Taxonomic history
Hesperocyoninae are basal canids that gave rise to th ...
. The Caninae includes all living canids and their most recent fossil relatives. Their fossils were first found in North America and dated to the Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define ...
era, then spreading to Asia at the end of the Miocene
The Miocene ( ) is the first of the Period and extends from about (Ma). The Miocene was named by Scottish geologist ; its name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern sea s ...
era, some 7 million to 8 million years ago.
Taxonomy and lineage
"Derived characteristics that distinguish the Caninae from other canids include small, simple, well-spacedpremolar
The premolars, also called premolar teeth
A tooth (plural teeth) is a hard, calcification, calcified structure found in the jaws (or mouths) of many vertebrates and used to Mastication, break down food. Some animals, particularly carnivores, al ...
s, a humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extremity of hu ...
without an entepicondylar foramenThe entepicondylar foramen is an opening in the distal (far) end of the humerus (upper arm bone) present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan ''Plesiorycteropus''. In most Neotominae and all T ...
, and a metatarsal 1 which is reduced to a proximal rudiment."
The genus ''Leptocyon
The genus ''Leptocyon'' (Greek: ''leptos'' slender + ''cyon'' dog) includes 11 species and was the first Caninae, canine. They were small and weighed around . They first appeared in North America around 34 million years ago in the Oligocene at th ...
'' (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 OrellanThe Orellan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), 34-32 million years ago. It is usually considered to fall within the Early Oligocene. T ...
era 34-32 million years ago, which was the beginning of the Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define ...
. 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. ''Leptocyon''s various species 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
Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In ...
'' or genus ''Eucyon
''Eucyon'' (Greek: : good, true; : dog) is an extinct
Extinction is the termination of a kind of organism
In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system ...
'' is not clear.
Phylogenetic relationships
The results of allozyme
Alloenzymes (or also called allozymes) are variant forms of an enzyme
Enzymes () are proteins that act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substr ...
and chromosome
A chromosome is a long DNA
Deoxyribonucleic acid (; DNA) is a molecule
File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings.
A mole ...
analyses have previously suggested several phylogenetic
In biology
Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanisms, ...
divisions:
DNA
Deoxyribonucleic acid (; DNA) is a molecule
File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings.
A molecule is an electrically neutral gro ...
analysis shows that the first three form monophyletic
300px, A cladogram of the primates, showing a ''monophyletic'' taxon: ''the simians'' (in yellow); a ''paraphyletic'' taxon: ''the prosimians'' (in cyan, including the red patch); and a ''polyphyletic'' group: ''the night-active primates, i.e., ...
clade
A clade (), also known as a monophyletic group or natural group, is a group of organism
In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms are composed of cells (cell ...
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
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is neces ...
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
The South American foxes (''Lycalopex''), commonly called ''raposa'' in Portuguese language, Portuguese, or ''zorro'' in Spanish language, Spanish, are a genus from South America of the subfamily Caninae. Despite their name, they are not Vulpes, ...
'' species, and ''Dusicyon
''Dusicyon'' is an extinct genus of South American canids. The type species is ''Dusicyon australis'', the Falkland Islands wolf. In 1914, Oldfield Thomas established this genus, in which he included the culpeo and other South American foxes. The ...
''.
References
External links
{{Taxonbar, from=Q2474088 Canines Extant Miocene first appearances