''Ischyrocyon'' is an extinct genus of

bear dog Amphicyonidae is an extinct family of terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene (around 45 mya), spread to Europe by the late Eocene (35 mya), and appear in Asia, an ...

s, of the subfamily

Amphicyoninae Amphicyoninae is a subfamily of extinct bear-dogs, large terrestrial carnivores belonging to the suborder Caniformia and which inhabited North America, Eurasia, and Africa from ~37.2—2.6 Ma. Amphicyoninae existed for approximately ~. A ...

, which inhabited North America during the Late

Miocene The Miocene ( ) is the first 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 means "less recent" ...

. It lived ~13.6—10.3 Ma ago, existing for approximately .

Behavior

In a study published in 2020, examination of the relative grinding area of the molars of ''Ischyrocyon'' indicated that it was purely carnivorous, and not omnivorous as previously assumed. Both ''Ischyrocyon'' and its relative, ''

Amphicyon ''Amphicyon'' ("ambiguous dog") is an extinct genus of large carnivorous bone-crushing mammals, popularly known as bear dogs, of the family Amphicyonidae, subfamily Amphicyoninae, from the Burdigalian Epoch until the late Pliocene, with the ...

'' possessed skeletal features that are characteristic of both ambush and pursuit living predators. As such, it is believed via this evidence that ''Ischyrocyon'' probably pursued prey for longer distances but at slower speeds than living ambush predators do. Upon catching up to its prey, ''Ischyrocyon'' probably grabbed its victims using its powerfully muscled forelimbs before killing them by tearing into the prey's ribcage or neck using its large, strong canines set in its narrow snout.

Fossil distribution

* Blair Junction,

Esmeralda County, Nevada Esmeralda County is a county in the southwestern portion of the U.S. state of Nevada. As of the 2020 census, the population was 729, making it the least populous county in Nevada. Esmeralda County does not have any incorporated communities. Its ...

~14.2—11.7 Ma. * Hemicyon Quarry Site,

Barstow Formation The Barstow Formation is a series of limestones, conglomerates, sandstones, siltstones and shales exposed in the Mojave Desert near Barstow in San Bernardino County, California.Dibblee, T.W., Jr. (1967). Areal Geology of the Western Mojave ...

San Bernardino County, California San Bernardino County (), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,18 ...

~14.0 Ma. * Adam Risley Ranch Site, Goliad Formation, Donley County, Texas ~12—11.7 Ma. * WaKeeney (Unit C)

Ogallala Formation The Ogallala Formation is a Miocene to early Pliocene geologic formation in the central High Plains of the western United States and the location of the Ogallala Aquifer. In Nebraska and South Dakota it is also classified as the Ogallala Group. N ...

Trego County, Kansas Trego County (standard abbreviation: TR) is a county located in the U.S. state of Kansas. As of the 2020 census, the county population was 2,808. Its county seat and largest city is WaKeeney. History Early history For many millennia, the Gr ...

~11.8—11.7 Ma. * Olcott Hill,

Snake Creek Formation The Snake Creek Formation is a Formation (geology), geologic formation in Nebraska. It preserves fossils dating back to the Neogene Period (geology), period. See also * List of fossiliferous stratigraphic units in Nebraska * Paleontology in Nebr ...

Sioux County, Nebraska Sioux County is a county in the U.S. state of Nebraska. As of the 2010 United States Census, the population was 1,311. Its county seat is Harrison. Sioux County is included in the Scottsbluff, NE Micropolitan Statistical Area. In the Nebrask ...

~11.9 Ma. * Iron Canyon Site, Dove Spring Formation,

Kern County, California Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield. Kern County comprises the Bakersfield, California, Metropolitan statistical area. The county ...

~11.8—11.9 Ma. *

Bluejay Quarry Site The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations a ...

, Ash Hollow Formation,

Antelope County, Nebraska Antelope County is a county located in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 6,295. Its county seat is Neligh. The county was formed in 1871. It received its name after a group of early settlers kill ...

~11.8 Ma.

References

Bear dogs Miocene bear dogs Miocene mammals of North America Barstovian Clarendonian Fossil taxa described in 1904 Prehistoric carnivoran genera {{paleo-carnivora-stub