''Leptomeryx'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...

of the family Leptomerycidae, endemic to

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

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

through

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 ...

38–24.8 Mya, existing for approximately . It was a small

deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

-like ruminant with somewhat slender body. Leptomeryx BW

Fossil distribution

Sites and species recovered: *Titus Canyon,

Inyo County, California Inyo County () is a County (United States), county in the Eastern California, eastern central part of the U.S. state of California, located between the Sierra Nevada and the state of Nevada. In the 2020 United States census, 2020 census, the po ...

''(L.blacki)'' ~30.6—33.9 Ma. *Anxiety Butte, Saskatchewan, Canada ''(L. sp., L. evansi)'' ~38—24.8 Ma. *Calf Creek, Saskatchewan, Canada, ''(L. mammifer)'' ~38—33.3 Ma. *Toadstool Park, Sioux County, Nebraska ''(L. speciosus)'' ~37.2—33.3 Ma. *Medicine Pole Hills,

Bowman County, North Dakota Bowman County is a county in the U.S. state of North Dakota. As of the 2020 census, the population was 2,993, and was estimated to be 2,886 in 2024, The county seat and the largest city is Bowman. History The legislature of the Dakota Ter ...

''(L. yoderi)'' ~38—33.9 Ma.Paleobiology database: Medicine Pole Hills collection
/ref>

References

* Webb, S.D., 1998. Hornless ruminants. pp. 463–476 ''in'' C.M. Janis, K.M. Scott, and L.L. Jacobs (''eds.'') ''Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals.'' Cambridge University Press, Cambridge. * Heaton, T.H. and Emry, R.J., 1996

pp. 581–608 ''in'' D.R. Prothero and R.J. Emry (''eds.'') ''The Terrestrial Eocene-Oligocene Transition in North America.'' Cambridge University Press, Cambridge. * Eocene Artiodactyla Oligocene Artiodactyla Eocene mammals of North America Oligocene mammals of North America White River Fauna Eocene United States Paleogene United States Eocene genus first appearances Chattian genus extinctions Fossil taxa described in 1853 Prehistoric Artiodactyla genera {{paleo-eventoedungulate-stub