Archaeocyon
Encyclopedia
Archaeocyon is a small extinct genus of the Borophaginae
within the family
Canidae
(terrestrial
canine
) which inhabited most of North America
during the Whitneyan
stage through Geringian
stage of the Oligocene
epoch 33.3—26.3 Ma Archaeocyon existed for approximately .
Species of Archaeocyon are among the earliest known borophagines, although a species of Otarocyon
has a slightly earlier first appearance.
(teeth) suggests a slightly more hypocarnivorous
(omnivorous) diet than the otherwise similar Hesperocyon
. The skeleton is also generalized, lacking specializations for running and retaining a plantigrade
foot posture.
A few derived features of the dentition support a relationship to Borophaginae and Caninae
(the subfamily that includes living canids), rather than to the basal canid subfamily Hesperocyoninae
. The temporal position of Archaeocyon suggests an affinity to borophagines because the first members of Caninae appear substantially earlier.
.
Borophaginae
The subfamily Borophaginae is an extinct group of canids called "bone crushing dogs" that were endemic to North America during the Oligocene to Pliocene and lived roughly 36—2.5 million years ago and existing for approximately .-Origin:...
within the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Canidae
Canidae
Canidae is the biological family of carnivorous and omnivorous mammals that includes wolves, foxes, jackals, coyotes, and domestic dogs. A member of this family is called a canid . The Canidae family is divided into two tribes: Canini and Vulpini...
(terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
canine
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
) which inhabited most of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
during the Whitneyan
Whitneyan
The Whitneyan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 33,300,000 to 30,800,000 years BP, a period of . It is usually considered to fall within the Early Oligocene...
stage through Geringian
Geringian
The Geringian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 30,800,000 to 26,300,000 years BP, a period of . It is usually considered to fall within the Oligocene epoch...
stage of the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
epoch 33.3—26.3 Ma Archaeocyon existed for approximately .
Species of Archaeocyon are among the earliest known borophagines, although a species of Otarocyon
Otarocyon
Otarocyon is an extinct genus "bone crushing dog" of the family Borophaginae and a terrestrial canine which was small in size endemic to North America during of the Oligocene epoch, ~33.9—20.6 Ma...
has a slightly earlier first appearance.
Taxonomy
Archaeocyon was a comparatively small and unspecialized dog. Its dentitionDentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
(teeth) suggests a slightly more hypocarnivorous
Hypocarnivore
A hypocarnivore is an animal that consumes less than 30% meat for its diet, the majority of which consists of nonvertebrate foods that may include fungi, fruits, and other plant material...
(omnivorous) diet than the otherwise similar Hesperocyon
Hesperocyon
Hesperocyon is an extinct genus of canids, family of Canidae and subfamily Hesperocyoninae which was endemic to North America from southern Canada to appearing during the Uintan age-Bridgerian age of the Mid-Eocene 42.5 mya—31.0 Ma. . Hesperocyon existed for approximately .-Taxonomy:Hesperocyon...
. The skeleton is also generalized, lacking specializations for running and retaining a plantigrade
Plantigrade
right|151px|thumb|Human skeleton, showing plantigrade habitIn terrestrial animals, plantigrade locomotion means walking with the podials and metatarsals flat on the ground. It is one of three forms of locomotion adopted by mammals...
foot posture.
A few derived features of the dentition support a relationship to Borophaginae and Caninae
Caninae
Caninae is the only living subfamily of Canidae. Many extinct species of Caninae were endemic to North America, living from 34 Ma—11,000 years ago. Some members of the endemic North American canines survived to the present time. This subfamily was recently revised by Tedford, Wang, and Taylor...
(the subfamily that includes living canids), rather than to the basal canid subfamily Hesperocyoninae
Hesperocyoninae
Hesperocyoninae is a subfamily of extinct canids.-Taxonomic history:Hesperocyoninae was named by Martin . The members of this subfamily were reassigned to the family Canidae by Xiaoming Wang in 1999....
. The temporal position of Archaeocyon suggests an affinity to borophagines because the first members of Caninae appear substantially earlier.
Morphology
Fossil specimens of two individuals' body mass were examined by Legendre and Roth. The first specimen was estimated to weigh 1.43 kg (3.15 lbs). The second specimen was estimated to weigh 1.49 kg (3.28 lbs).Species
Three species of Archaeocyon have been described. The two earlier species, A. pavidus and A. leptodus, differ primarily in size, with A. leptodus being larger. The third species, A. falkenbachi, is the size of A. leptodus and differs from other Archaeocyon species in having a shorter, broader skullSkull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
.
Fossil distribution
- Kew Quarry, Sespe FormationSespe FormationThe Sespe Formation is a widespread fossiliferous sedimentary geologic unit in southern and south central California in the United States. It is of nonmarine origin, consisting predominantly of sandstones and conglomerates laid down in a riverine, shoreline, and floodplain environment between the...
, Ventura County, CaliforniaVentura County, CaliforniaVentura County is a county in the southern part of the U.S. state of California. It is located on California's Pacific coast. It is often referred to as the Gold Coast, and has a reputation of being one of the safest populated places and one of the most affluent places in the country...
. - North Blue Basin Site, John Day FormationJohn Day FormationThe John Day Formation is series of rock strata exposed in the John Day River basin of north-central Oregon in the United States. The strata, which vary in age from 39 million years to 18 million years, were formed mainly from ashfalls from volcanoes to the west...
, Grant County, OregonGrant County, OregonGrant County is a county located in the U.S. state of Oregon. It is included in the 8 county definition of Eastern Oregon. In 2010, its population was 7,445. It is named for President Ulysses S. Grant, who served as an army officer in the Oregon Territory, and at the time of the county's creation...
. - Canyon Ferry Reservoir, Lewis and Clark County, MontanaLewis and Clark County, Montana-National protected areas:* Flathead National Forest * Helena National Forest * Lewis and Clark National Forest * Lolo National Forest * Rocky Mountain Front Conservation Area -Demographics:...
. - Roundhouse Rock, Brule Formation, Morrill County, NebraskaMorrill County, Nebraska-History:Morrill County was formed in 1908 "carved out of Cheyenne County". It was named after Charles Henry Morrill, a president of the Lincoln Land Company.-Demographics:...
and other Nebraska sites. - White Butte Site, Killdeer Formation, Slope County, North DakotaSlope County, North DakotaThere were 313 households out of which 30.0% had children under the age of 18 living with them, 64.5% were married couples living together, 3.8% had a female householder with no husband present, and 28.8% were non-families. 27.2% of all households were made up of individuals and 10.5% had someone...
.