TAXONOMY & NOMENCLATURE * *How Do We Know This? Like living animals, fossil remains of once-living animals
classified and grouped according to their relationships
each other and to their ancestors.
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Artiodactyla (pigs, camels, deer, giraffes, cattle, and their kin) Family: Antilocapridae (includes only one living member - the pronghorn, Antilocacapra americana and many fossil taxa) Subfamily: Antilocaprinae (have sheaths on horns that are shed and no 'burrs' on horn core shafts) Tribe: Stockoceratini (all extinct genera) Genus: Capromeryx Species: Capromeryx minor
Taxonomic History and Nomenclature
Scientific Name: 'capro' is a Latin word meaning 'male goat'; 'meryx' is from the Greek for 'ruminant"; 'minor' is Latin for 'smaller'
Common Name: Dwarf Pronghorn
The antilocaprids are in need of species-level revision. (Davis 2007)
Traditionally this family has been placed with bovids based on horn, teeth, and biochemical characters but molecular data aligns Antilocapridae with the Giraffidae. (Hernández Fernández & Vrba 2005; Murray 2006; Janis 2000)
Most classification for members of this family based on horn core anatomy. (Davis 2007)
Species of Capromeryx can also be distinguished on the basis of tooth size and shape. (Jiménez-Hidalgo et al 2004)
The family to which the dwarf-pronghorn belongs (Antilocapridae) first appears in North America between 16 and 20 million years ago.
Unlike other hoofed animals like horses, camels and tapirs, the antilocaprids did not migrate into other continents from North America. (Janis and Manning 1998)
Species in the genus Capromeryx became progressively smaller
Tiny C. minor is the latest of four known species to evolve; it lived between about 300,000 and 11,000 years ago.
C.minor is 66 % smaller than the earliest Capromeryx species (Davis 2007) (Morgan & Morgan 1995)
The genus Capromeryx dates to at least 5 million years ago (Davis 2007)
Capromeryx is not directly related to the modern pronghorn genus Antilocapra; both genera lived during the latest Pleistocene times and are known from La Brea asphalt deposits. (Morgan and Morgan 1995; Janis and Manning 1998; Davis 2007).
The antilocaprines declined significantly in diversity between Late Miocene and modern times; now the family is represented by only one animal, the North American Pronghorn (Antilocapra americana) (Janis 2000)
DISTRIBUTION & HABITAT * *How Do We Know This? Scientists use knowledge of the earth's rocks, global
plate tectonic movements,
and the chemical process of fossilization
to make sense of
fossil distribution patterns and ancient habitats.
(Davis 2007) (Kurtén & Anderson 1980) (Murray 2006)
For the species, Capromeryx minor: California, Texas, New Mexico (Davis 2007)
For all the species of Capromeryx: Arizona, California, Florida, Kansas, Nebraska, New Mexico, Texas, Washington, Mexico (Davis 2007)
Grassy plains with clusters of trees and shrubs; open grassy uplands (Kurtén & Anderson 1980)
Need trees or tall vegetation for refuge. (Murray 2006)
PHYSICAL CHARACTERISTICS* *How Do We Know This? Careful study of fossil bone or tooth anatomy yields much
about placement and strength of muscles, tendons, ligaments,
nerves, and blood vessels.
In rare cases, skin and hair impressions or actual skin
or hair is preserved.
Body weight is more difficult to gauge because fat leaves
no impression on the skeleton.
(Janis & Manning 1998) (Murray 2006)
Estimated Body Weight: Estimated 10 kg (22 lb) (Murray 2006) Estimated Height at Shoulder: 60 cm (24 in); similar in size to African gazelle (Gazella) (Murray 2006) Tail Length: Short tail Horns: Two horns are each forked with two prongs as in modern Pronghorn;
larger rear-ward tine only 10 cm.(3.9 in) with the front tine much shorter.
A very small, slender, gazelle-like ungulate with two-tined horn cores.
High crowned (hypsodont) teeth adapted for an abrasive diet.
Lower third molar lacks a fourth lobe. (Murray 2006)
No upper incisor (Janis & Manning)
Yes, two sexes distinct in fossil populations; males larger. (Janis & Manning 1998)
Other Physical Characteristics
Long limbs modified for fast running.
BEHAVIOR & ECOLOGY* *How Do We Know This? Since direct observation of a fossil animal's behavior
isn't possible, paleontologists use
comparison and contrast with living animals for guidance.
Tracks can sometimes
reveal further clues.
(Janis and Manning 1998) (Jarman 1974)
Some authors argue for a gregarious herding lifestyle, similar to that of modern gazelle and Pronghorn, for members of the Capromeryx genus (Janis and Manning 1998)
But the extrememly small size of C. minor may imply small groups living a discrete lifestyle (Davis 2007)
Many members of the family are part-time territorial
(Jarman 1974; Janis and Manning 1998)
Males defend resource-based territories.
Highly adapted for running
The living Pronghorn who share a common ancestor with C. minor are the fastest animals in North America.
Informally known as "everybody's lunch" (Davis 2007)
DIET & FEEDING* *How Do We Know This? Clues to fossil mammals' diets come from teeth,skull shape,
from fossil dung and gut contents, from
lab analysis of oxygen
in bone and teeth,
looking at diets of similar modern animals.
(Janis & Manning 1998)
The high-crowned (hypsodont) teeth and
a narrow muzzle probably reflect and intermediate browsing/grazing feeding style (Janis & Manning 1998)
REPRODUCTION & DEVELOPMENT * *How do We Know This? Isotope studies of elements present fossil bones and tusks
about timing of reproductive stress, and timing of nursing.
Clues to stages of development come from tooth
replacement patterns and closure of sutures
in skull and limb bones.
Mortality and Life Stages
Not known at present, but may have many similarities to modern Pronghorn.
DISEASES AND PATHOLOGY*
*How do We Know This? Abnormalities in fossils bones may show
evidence of arthritis, cancer, nutritional stress, fractures and more.
Important Web Resources (including where to view fossils in museums):
The Paleobiology Database -- This site is a scientific organization run by paleontological researchers from around the world. It features taxonomic and distribution information for the entire fossil record.