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Temporal range: Early Miocene–recent
Pronghorn antelope.jpg
Pronghorns in Fort Keogh, Montana
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Suborder: Ruminantia
Infraorder: Pecora
Family: Antilocapridae
J. E. Gray, 1866
Type genus
Ord, 1815

See text

The Antilocapridae are a family of ruminant artiodactyls endemic to North America. Their closest extant relatives are the giraffids. [1] Only one species, the pronghorn (Antilocapra americana), is living today; all other members of the family are extinct. The living pronghorn is a small ruminant mammal resembling an antelope.



In most respects, antilocaprids resemble other ruminants. They have a complex, four-chambered stomach for digesting tough plant matter, cloven hooves, and small, forked horns. Their horns resemble those of the bovids, in that they have a true horny sheath, but, uniquely, they are shed outside the breeding season, and subsequently regrown. Their lateral toes are even further diminished than in bovids, with the digits themselves being entirely lost, and only the cannon bones remaining. Antilocaprids have the same dental formula as most other ruminants:


The antilocaprids are ruminants of the clade Pecora. Other extant pecorans are the families Giraffidae (giraffes), Cervidae (deer), Moschidae (musk deer), and Bovidae (cattle, goats and sheep, wildebeests and allies, and antelopes). The exact interrelationships among the pecorans have been debated, mainly focusing on the placement of Giraffidae, but a large-scale ruminant genome sequencing study in 2019 suggested that Antilocapridae are the sister taxon to Giraffidae, as shown in the cladogram below. [2]



The ancestors of pronghorn diverged from the giraffids in the Early Miocene. [2] This was in part of a relatively late mammal diversification following a climate change that transformed subtropical woodlands into open savannah grasslands. [2]

The antilocaprids evolved in North America, where they filled a niche similar to that of the bovids that evolved in the Old World. During the Miocene and Pliocene, they were a diverse and successful group, with many different species. Some had horns with bizarre shapes, or had four, or even six, horns. Examples include Osbornoceros , with smooth, slightly curved horns, Paracosoryx, with flattened horns that widened to forked tips, Ramoceros , with fan-shaped horns, and Hayoceros , with four horns. [3] [4]


Related Research Articles

<span class="mw-page-title-main">Ungulate</span> Group of animals that walk on the tips of their toes or hooves

Ungulates are members of the diverse clade Euungulata, which primarily consists of large mammals with hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including equines, rhinoceroses, and tapirs; and Artiodactyla including cattle, antelope, pigs, giraffes, camels, sheep, deer, and hippopotamuses, among others. Cetaceans such as whales, dolphins, and porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. Two other orders of ungulates, Notoungulata and Litopterna, both native to South America, became extinct at the end of the Pleistocene, around 12,000 years ago.

<span class="mw-page-title-main">Artiodactyl</span> Order of mammals

Artiodactyls are placental mammals belonging to the order Artiodactyla. Typically, they are ungulates which bear weight equally on two of their five toes: the third and fourth, often in the form of a hoof. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, most perissodactyls bear weight on an odd number of the five toes. Another difference between the two is that many artiodactyls digest plant cellulose in one or more stomach chambers rather than in their intestine as perissodactyls do. The advent of molecular biology, along with new fossil discoveries, found that cetaceans fall within this taxonomic branch, being most closely related to hippopotamuses. Some modern taxonomists thus apply the name Cetartiodactyla to this group, while others opt to include cetaceans within the existing name of Artiodactyla. Some researchers use "even-toed ungulates" to exclude cetaceans and only include terrestrial artiodactyls, making the term paraphyletic in nature.

<span class="mw-page-title-main">Caprinae</span> Subfamily of mammals

The subfamily Caprinae, also sometimes referred to as the tribe Caprini, is part of the ruminant family Bovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine.

<span class="mw-page-title-main">Bovidae</span> Family of mammals belonging to even-toed ungulates

The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, yaks, bison, buffalo, antelopes, sheep and goats. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, the family Bovidae consists of 11 major subfamilies and thirteen major tribes. The family evolved 20 million years ago, in the early Miocene.

<span class="mw-page-title-main">Giraffidae</span> Family of mammals belonging to even-toed ungulates

The Giraffidae are a family of ruminant artiodactyl mammals that share a common ancestor with deer and bovids. This family, once a diverse group spread throughout Eurasia and Africa, presently comprises only two extant genera, the giraffe and the okapi. Both are confined to sub-Saharan Africa: the giraffe to the open savannas, and the okapi to the dense rainforest of the Congo. The two genera look very different on first sight, but share a number of common features, including a long, dark-coloured tongue, lobed canine teeth, and horns covered in skin, called ossicones.

<i>Antilocapra</i> Genus of mammals

Antilocapra is a genus of the family Antilocapridae, which contains only a single living species, the pronghorn (Antilocapra americana). Another species, the Pacific pronghorn, lived in California during the Late Pleistocene and survived as recently as 12,000 BP. The name means "antelope-goat".

<span class="mw-page-title-main">Pecora</span> Infraorder of mammals

Pecora is an infraorder of even-toed hoofed mammals with ruminant digestion. Most members of Pecora have cranial appendages projecting from their frontal bones; only two extant genera lack them, Hydropotes and Moschus. The name "Pecora" comes from the Latin word pecus, which means "cattle". Although most pecorans have cranial appendages, only some of these are properly called "horns", and many scientists agree that these appendages did not arise from a common ancestor, but instead evolved independently on at least two occasions. Likewise, while Pecora as a group is supported by both molecular and morphological studies, morphological support for interrelationships between pecoran families is disputed.

<i>Sivatherium</i> Extinct genus of mammals

Sivatherium is an extinct genus of giraffids that ranged throughout Africa to the Indian subcontinent. The species Sivatherium giganteum is, by weight, one of the largest giraffids known, and also one of the largest ruminants of all time.

<span class="mw-page-title-main">Ossicone</span> Horn-like structure of giraffes, okapi, and extinct relatives

Ossicones are columnar or conical skin-covered bone structures on the heads of giraffes, male okapi, and some of their extinct relatives. Ossicones are distinguished from the superficially similar structures of horns and antlers by their unique development and a permanent covering of skin and fur.

<i>Osbornoceros</i> Extinct genus of mammals

Osbornoceros is an extinct artiodactyl genus of the family Antilocapridae. All antilocaprid species are extinct except for the pronghorn. Osbornoceros osborni is the only known species of the genus Osbornoceros. Osbornoceros lived during the Late Miocene around 7 to 6 million years ago in what is now North America. It is well represented in fossil discoveries, with nearly a dozen specimens having been found to date. All come from the Chamita Formation in a quarry near Lyden, New Mexico, the site of numerous other finds such as that of Chamitataxus, a prehistoric badger that lived at the same time. The holotype specimen of Osbornoceros was discovered in 1937 and many more were found nearby during further expeditions.

Hexameryx is an extinct monospecific genus of the artiodactyl family Antilocapridae endemic to North America. It lived during the Pliocene epoch 5.3—4.9 mya. It had six well-forked horns.

<span class="mw-page-title-main">Palaeomerycidae</span> Extinct family of pecorans

The Palaeomerycidae is an extinct family of Neogene ruminants belonging to the infraorder Pecora. Palaeomerycids lived in Europe and Asia exclusively during the Miocene, coevolving with cervids, bovids, moschids, and tragulids there as part of a dramatic radiation of ruminants by the early Miocene.

<span class="mw-page-title-main">Pronghorn</span> Species of North American hoofed mammal

The pronghorn is a species of artiodactyl mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American antelope, prong buck, pronghorn antelope and prairie antelope, because it closely resembles the antelopes of the Old World and fills a similar ecological niche due to parallel evolution. It is the only surviving member of the family Antilocapridae.

<i>Ramoceros</i> Extinct genus of mammals

Ramoceros is an extinct genus of the artiodactyl family Antilocapridae endemic to Middle Miocene (Clarendonian) North America.

<i>Merycodus</i> Extinct genus of mammals

Merycodus is an extinct genus of the artiodactyl family Antilocapridae. Fossils of this genus have been found in the Santa Fe Group of New Mexico.

<i>Stockoceros</i> Extinct genus of mammals

Stockoceros is an extinct genus of the North American artiodactyl family Antilocapridae (pronghorns), known from what is now Mexico and the southwestern United States. The genus survived until about 12,000 years ago, and was present when Paleo-Indians reached North America.

<i>Tetrameryx</i> Extinct genus of mammals

Tetrameryx is an extinct genus of the North American artiodactyl family Antilocapridae, known from Mexico, the western United States, and Saskatchewan in Canada.

<i>Merriamoceros</i> Extinct genus of mammals

Merriamoceros is an extinct genus of pronghorn. It is known from a single species, which is also the type species, M. coronatus.

<i>Capromeryx</i> Extinct genus of mammals

Capromeryx was a genus of dwarf pronghorns (Antilocapridae) that originated in North America during the Pliocene about 5 million years ago. The closest living relative and only surviving member of the family is the North American pronghorn.


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