''Dinictis'' is a

genus Genus ( plural genera ) 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 the hierarchy of biological classification, genus com ...

of the

Nimravidae Nimravidae is an extinct family (biology), family of carnivorans, sometimes known as false saber-toothed cats, whose fossils are found in North America and Eurasia. Not considered to belong to the true cats (family Felidae), the nimravids are gen ...

, an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

feliform Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including cats (large and small), hyenas, mongooses, viverrids, and related taxa. Feliformia stands in contrast to the other suborder of Carnivora, Caniform ...

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

ian

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s, also known as "false

saber-toothed cat Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million until ...

s". Assigned to the

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 subfamily botanical names with "-oideae", and zoologi ...

Nimravinae The Nimravinae are a subfamily of the Nimravidae, an extinct family of feliform mammalian carnivores sometimes known as false saber-toothed cats. They were endemic to North America, Europe, and Asia from the Middle Eocene through the Late Mi ...

, ''Dinictis'' was endemic to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

from the Late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

to Early

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 recen ...

epochs (37.2—20.4 million years ago), existing for about .

Taxonomy

''Dinictis'' was named by American paleontologist

Joseph Leidy Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist. Leidy was professor of anatomy at the University of Pennsylvania, later was a professor of natural history at Swarthmore ...

in 1854. Its type is ''Dinictis felina''. It was assigned to the Nimravidae by Leidy (1854); and to the Nimravinae by Flynn and Galiano (1982), Bryant (1991), and Martin (1998). In a 2016 study, the genus was found to contain only the species ''Dinictis felina''.

Description

''Dinictis'' had a sleek body long, short legs high with only incompletely retractable claws, powerful jaws, and a long tail. It was very similar to its close relative, ''

Hoplophoneus ''Hoplophoneus'' (Greek: "murder" (phonos), "weapon" (hoplo)) is an extinct genus of the family Nimravidae, endemic to North America during the Late Eocene to Early Oligocene epochs (35–29 mya), existing for approximately . Taxonomy In 20 ...

''. The shape of its skull is reminiscent of a felid skull rather than of the extremely short skull of the

Machairodontinae Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million until ...

. Compared with those of the more recent machairodonts, its upper canines were relatively small, but they nevertheless distinctly protruded from its mouth. Below the tips of the canines, its lower jaw spread out in the form of a lobe. ''Dinictis'' walked

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

(flat-footed), unlike modern

felids Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the do ...

. It looked like a small

leopard The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, a ...

and evidently its mode of life was similar to that of a leopard. It was probably not so particular about its food as its descendants, since the reduction of its teeth was still in the early stages and ''Dinictis'' had not forgotten how to chew. In its own environment, it would have been a powerful predator.

Ecology

It lived in the plains of

with fossils found in

Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...

North Dakota North Dakota () is a U.S. state in the Upper Midwest, named after the Native Americans in the United States, indigenous Dakota people, Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north a ...

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

, and

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. ''Dinictis'' likely evolved from an early ''Miacis''-like ancestor that lived in the Paleocene.

References

Benes, Josef. Prehistoric Animals and Plants. Pg. 204. Prague: Artua, 1979. {{Nimravidae Nimravidae Paleogene mammals of North America White River Fauna Eocene carnivorans Oligocene feliforms Aquitanian genus extinctions Prehistoric carnivoran genera