''Cynodesmus'' ("dog link") is an extinct genus of
omnivorous
An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...
canine which inhabited
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
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 ...
living from 33.3—-26.3 Ma and existed for approximately .
''Cynodesmus'' was one of the first canids to truly look dog-like. At around in length, it was about the same size as a modern
coyote
The coyote (''Canis latrans''), also known as the American jackal, prairie wolf, or brush wolf, is a species of canis, canine native to North America. It is smaller than its close relative, the Wolf, gray wolf, and slightly smaller than the c ...
, but had a shorter
skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate.
In the human, the skull comprises two prominent ...
, heavier tail, and longer rump. The shape of its limbs suggests that ''Cynodesmus'' was not a very good runner compared to most other canids; it probably attacked prey from an ambush. Unlike modern dogs, it had five toes on each foot, bearing partially retractable
claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthro ...
s.
Taxonomy
''Cynodesmus'' once included numerous species of
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 ...
and
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 ...
canid with highly carnivorous (
hypercarnivorous
A hypercarnivore is an animal that has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant example ...
)
dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...
s. A revision of the genus by Wang (1994) indicates that most species previously placed in ''Cynodesmus'' are unrelated to the
type
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* ...
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...
as ''Cynodesmus'',
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 the ...
. The remaining genera are placed in the subfamilies
Borophaginae
The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America d ...
and
Caninae
Caninae (whose members are known as canines () is the only living subfamily within Canidae, alongside the extinct Borophaginae and Hesperocyoninae. They first appeared in North America, during the Oligocene around 35 million years ago, subsequent ...
.
With unrelated species removed, ''Cynodesmus'' is currently restricted to the type species and the closely related ''C. martini'' (Wang, 1994).
Studies using the old conception of ''Cynodesmus'' considered it to be the ancestor of '' Tomarctus'' (16-23 Ma) from which
wolves
The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...
,
dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...
s, foxes and fennecs developed. ''Cynodesmus'' is a good example of
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...
because of other species such as the '' Borophagus'', the largest and most dominant canids of the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58North American Coyote