The Antilocapridae are a family of ruminant Artiodactyla endemic to North America. Their closest extant taxon relatives are the Giraffidae.
Description
In most respects, antilocaprids resemble other
ruminants. They have a complex, four-chambered stomach for digesting tough plant matter,
Cloven hoof, and small, forked horns. Their horns resemble those of the
, 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
remaining. Antilocaprids have the same
dentition as most other ruminants: .
Classification
The antilocaprids are
of the clade
Pecora. Other extant pecorans are the families
Giraffidae (
),
Cervidae (deer),
Moschidae (
musk deer), and
Bovidae (
Bovini,
Caprinae,
Alcelaphinae, and
). 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.
Evolution
The ancestors of pronghorn diverged from the giraffids in the
Early Miocene.
[ This was in part of a relatively late mammal diversification following a climate change that transformed subtropical into open savannah .][
]
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.
Species
-
Subfamily Antilocapra
-
Tribe Antilocaprini
-
Genus Antilocapra
-
Pronghorn - pronghorn
-
A. a. americana - Pronghorn
-
A. a. mexicana - Mexican pronghorn
-
A. a. peninsularis - Baja California pronghorn
-
A. a. sonoriensis - Sonoran pronghorn
-
A. a. oregona - Pronghorn
-
† Antilocapra pacifica
-
Genus extinction Texoceros
-
Texoceros altidens
-
Texoceros edensis
-
Texoceros guymonensis
-
Texoceros minorei
-
Texoceros texanus
-
Texoceros vaughani
-
Tribe †Ilingoceratini
-
Genus † Ilingoceros
-
Ilingoceros alexandrae
-
Ilingoceros schizoceros
-
Genus † Ottoceros
-
Ottoceros peacevalleyensis
-
Genus † Plioceros
-
Plioceros blicki
-
Plioceros dehlini
-
Plioceros floblairi
-
Genus † Sphenophalos
[
]
-
Sphenophalos garciae
-
Sphenophalos middleswarti
-
Sphenophalos nevadanus
-
Tribe †Proantilocaprini
-
Tribe Stockoceratini
-
Genus † Capromeryx - (junior synonym Breameryx)
-
Capromeryx arizonensis - (junior synonym B. arizonensis)
-
Capromeryx furcifer - (junior synonyms B. minimus, ''C. minimus)
-
Capromeryx gidleyi - (junior synonym B. gidleyi)
-
Capromeryx mexicana - (junior synonym B. mexicana)
-
Capromeryx minor - (junior synonym B. minor)
-
Capromeryx tauntonensis
-
Genus † Ceratomeryx
[
]
-
Genus † Hayoceros
-
Hayoceros barbouri
-
Hayoceros falkenbachi
-
Genus † Hexameryx
-
Genus † Hexobelomeryx
[
]
-
Hexobelomeryx fricki
-
Hexobelomeryx simpsoni
-
Genus † Stockoceros
-
Stockoceros conklingi (junior synonym S. onusrosagris) conklingi'' skeleton]]
-
Genus † Tetrameryx
-
Tetrameryx irvingtonensis
-
Tetrameryx knoxensis
-
Tetrameryx mooseri
-
Tetrameryx shuleri
-
Tetrameryx tacubayensis
-
Subfamily †Merycodontinae
-
Genus † Cosoryx
-
Cosoryx cerroensis
-
Cosoryx furcatus
-
Cosoryx ilfonensis
-
Genus † Merriamoceros
-
Genus † Merycodus (syn. Meryceros and Submeryceros)
-
Merycodus crucensis
-
Merycodus hookwayi
-
Merycodus joraki
-
Merycodus major
-
Merycodus minimus
-
Merycodus minor
-
Merycodus necatus
-
Merycodus nenzelensis
-
Merycodus prodromus
-
Merycodus sabulonis
-
Merycodus warreni
-
Genus † Paracosoryx
-
Paracosoryx alticornis
-
Paracosoryx burgensis
-
Paracosoryx dawesensis
-
Paracosoryx furlongi
-
Paracosoryx loxoceros
-
Paracosoryx nevadensis
-
Paracosoryx wilsoni
-
Genus † Ramoceros
-
Ramoceros brevicornis
-
Ramoceros marthae
-
Ramoceros merriami
-
Ramoceros osborni
-
Ramoceros palmatus
-
Ramoceros ramosus
