''Capromeryx'' (dwarf pronghorn) is an extinct genus of dwarf pronghorns (

Antilocapridae The Antilocapridae are a family of ruminant artiodactyls endemic to North America. Their closest extant relatives are the giraffids. Only one species, the pronghorn (''Antilocapra americana''), is living today; all other members of the family ...

) that originated in North America during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58 Antilocaprines began to decline in diversity during the Late

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

, and the closest living relative and only surviving antilocaprine is the North American pronghorn ('' Antilocapra americana'').

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 comprise an active Paleontological site, paleontological research site in urban Los Angeles. Hancock Park was formed around a group of tar pits where natural Bitumen, asphalt (also called asphaltum, bitumen, or pitch; ''brea'' ...

in Los Angeles, where enough bones have been unearthed to produce a full skeleton sample of '' Capromeryx minor''. 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. Capromeryx arizonensis FLMNH

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 artiodactyls 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 that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

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 ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

coast, as well as in

Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Sonora Sonora (), officially Estado Libre y Soberano de 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 divided into Municipalities of Sonora, 72 ...

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

, and near

Mexico City Mexico City is the capital city, capital and List of cities in Mexico, largest city of Mexico, as well as the List of North American cities by population, most populous city in North America. It is one of the most important cultural and finan ...

. 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 1.8 million – 250,000 years Before Present, BP.

and Rancholabrean 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 United States. It is often referred to as Washington State to distinguish it from the national capital, both named after George Washington ...

and from Central

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

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 BP, a period of .Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

and

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. These two earlier species were larger and heavier than the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

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 (geology), epoch in the geologic time scale that extends from 5.33 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

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 BP, a period of .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

It is unknown why exactly ''Capromeryx'' disappeared from the North American landscape.

References

Bibliography

* {{Taxonbar, from=Q3657910, from2=Q2707870 Holocene extinctions Pliocene first appearances Prehistoric Artiodactyla genera Prehistoric pronghorns Pliocene mammals of North America Pleistocene mammals of North America Fossil taxa described in 1902