''Capromeryx'' (dwarf pronghorn) was a genus of dwarf pronghorns (

Antilocapridae The Antilocapridae are a family of artiodactyls endemic to North America. Their closest extant relatives are the giraffids with which they comprise the superfamily Giraffoidea. Only one species, the pronghorn (''Antilocapra americana''), is li ...

) that originated in North America during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 The closest living relative and only surviving member of the family is the North American pronghorn (''

Antilocapra americana The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...

'').

Description

''Capromeryx'' were the smallest members of the pronghorn family Antilocapridae. They are recognized by having two upright horns that are conical in shape (wider at the base and tapering toward the top). The United States distribution of this genus includes: Arizona, California, Florida, New Mexico, Texas, and Washington. Fossils have also been found in the Mexican states of: Chihuahua, Sonara, and Baja California. Many ''Capromeryx'' fossils have been found in tar pits, and juveniles are especially common. One such location is the Rancho

La Brea Tar Pits La Brea Tar Pits is an active paleontological research site in urban Los Angeles. Hancock Park was formed around a group of tar pits where natural asphalt (also called asphaltum, bitumen, or pitch; ''brea'' in Spanish) has seeped up from the gro ...

in Los Angeles, where enough bones have been unearthed to produce a full skeleton sample of ''

Capromeryx minor ''Capromeryx'' (dwarf pronghorn) was a genus of dwarf pronghorns (Antilocapridae) that originated in North America during the Pliocene about 5 million years ago (the exact range of their presence on the landscape is still not known, but the most re ...

''. Much like the living pronghorns that exist today, the habitat that these animals were thought to inhabit were grassy plains with some shrubs and large trees for them to take refuge in. It is still unknown what exactly they ate and how they interacted socially but it is speculated that they were similar in many ways to their living relatives, the North American Pronghorn. Pronghorn Yellowstone

Classification

Though the identification of ''Capromeryx'' often relies on the basis of tooth size and shape, the description and acceptance of the various species of ''Capromeryx'' requires the fossil presence of horn cores (the bony inner shaft of the horn). Some species have not yet produced these cores and therefore have not been recognized as distinct species. Fossil specimens are instead classified by size. Fossils identified as the family

are similarly distributed into genus by size, with ''Capromeryx'' being the smallest of the known Pronghorns. There are several species of ''Capromeryx'', however only four have been formally recognized, and even these are likely all the same: * ''Capromeryx arizonensis'' * ''Capromeryx furicifer'': one of the smallest artiodactlys known, being at the shoulder and in weight. * ''Capromeryx tauntonensis'' * ''Capromeryx minor'': discovered in the

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and elsewhere. It has been found at least as far east as the coast of Texas. It stood about 60 centimetres tall at the shoulders and weighed about 10 kilograms (22 lb). It is unclear whether females had horns as well as males. Each horn consists of a pair of short, straight points that sprout from a single base on either side of the head, with the two prongs parallel rather than diverging as in ''Tetrameryx'' and ''Stockoceros''. Some described but unrecognized species include: * ''Capromeryx mexicana'' * ''Capromeryx gidleyi'' ''Capromeryx furcifer'' would have priority as the proper name for the Late Irvingtonian through Rancholabrean species in which the anterior prong is less than 50% the height of the posterior prong. Its fossils have also been found at least as far east at as the

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

coast, as well as in

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 ...

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, and near

Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...

. Specimens of this species (and its synonyms) date to the Late

Irvingtonian The Irvingtonian North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), spanning from 1.9 million – 250,000 years BP. ...

and

Rancholabrean The Rancholabrean North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from less than 240,000 years to 11,000 years BP, a p ...

periods. Two earlier species are known: ''Capromeryx tautonensis'' from

Washington state Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...

and from Central

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

in the Early

Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years Before Present, BP, a period of .

, and ''Capromeryx arizonensis'' from the Late Blancan in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

. These two earlier species were larger and heavier than the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

species.

Discovery and species

The earliest fossil records of ''Capromeryx'' are dated to 5 million years ago, during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 The first description of ''C. furcifer'' was in 1902 by W.D. Matthew in New Mexico, but it has been found in other locations as well but by other individuals (Hay Springs, Nebraska and La Brea, California are two such locations). The first description of ''C. arizonensis'' was in 1942 by M. F. Skinner also found in New Mexico at two sites called Pearsons Mesa and Caballo. These sites are described as being late

. James K. Morgan and Neil H. Morgan were the first to describe ''C. tauntonensis'' in 1995 in the ''

Journal of Vertebrate Paleontology The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolu ...

.'' They discovered the fossils that included horn cores and teeth during a dig (from 1988 to 1992) in Blancan sediments in Adams County, Washington.

Behavior

It is thought by some biologists that it lived in forests and underbrush, where its small size would have helped it to hide. It is unlikely that it lived in open prairies, since it would not have been fast enough to outrun the predators of that time.

Extinction

Though it is unknown why exactly ''Capromeryx'' disappeared from the North American landscape, it is evident that this genus began to decline in diversity around the time of 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 recen ...

References

Bibliography

* {{Taxonbar, from=Q3657910, from2=Q2707870 Holocene extinctions Pliocene first appearances Prehistoric even-toed ungulate genera Prehistoric pronghorns Pliocene mammals of North America Pleistocene mammals of North America