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Lama glama |
The four llamas and two camels are camelids: members of the biological family Camelidae, the only family in the suborder Tylopoda.
Camelids are even-toed ungulates: they are classified in the same orderOrder is one of the levels of scientific classification of organisms. Orders are grouped into classes and themselves contain families. The standard groupings of taxonomy from most general to most specific are: Domain Kingdom Phylum (animals); Division (pl as the pigs, peccaries and hippos (suborder SuidaeThe Suidae or suids are the biological family to which pigs belong. Up to sixteen species are currently recognised, including the domestic pig Sus scrofa or S. domesticus''. They are classified into between four and eight genera. In addition to numerous s) and the extraordinarily successful and diverse suborder RuminantiaRuminantia White-tailed Deer : Animalia : Chordata : Mammalia : Artiodactyla Ruminantia Families Tragulidae Moschidae Cervidae Giraffidae Antilocapridae Bovidae The biological suborder Ruminantia includes many of the well-known large grazing or browsing m (which includes cattle, goats, antelope and many others). Like many of the Ruminantia, camelids tend to be large and strictly herbivorous.
Camelids differ from other ruminants in several ways. They have a three-chambered rather than a four-chambered digestive tract; an upper lip that is split in two with each part separately mobile; an isolated incisor in the upper jaw; and uniquely among mammals, elliptical blood corpuscles ( erythrocytes). They have long legs that, because they lack tensor skin to bridge between thigh and body, look longer still, and although they have hooves, only the front part of the hoof touches the ground and the main weight of the animal is borne by the tough, leathery sole-pads. The South American camelids, adapted to steep and rocky terrain, can move the pads on their toes to maintain grip. The two Afro-Asian species have developed extensive adaptations to fit them to life in harsh, near-waterless environments.
Camelids are unusual in that their modern distribution is almost a mirror-image of their origin. Camelids first appeared very early in the evolution of the even-toed ungulates, around 45 million years ago during the late EoceneThe Eocene epoch (55-37 mya) is a major division of the geologic timescale and the second epoch of the Tertiary period in the Cenozoic era. The Eocene spans the time from the end of the Paleocene epoch to the beginning of the Oligocene epoch. The start of, in present-day North AmericaNorth America is the third largest continent in area and the fourth ranked in population. It is bounded on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the North Pacific Ocea. The family diversified and prospered but remained confined to the North American continent until only about 2 or 3 million years ago, when representatives arrived in AsiaThe continent of Asia is defined by subtracting Europe and Africa from the great land mass of Africa-Eurasia. The boundaries are vague, especially between Asia and Europe: Asia and Africa meet somewhere near the Suez Canal. The boundary between Asia and E, and (after the formation of the Isthmus of Panama) South America.
The original camelids of North America remained common until the quite recent geological past, but then disappeared, possibly as a result of hunting or habitat alterations by the earliest human settlers. Three species groups survived: the Dromedary of northern Africa and south-west Asia; the Bactrian Camel of eastern Asia; and the South American group, which has now diverged into a range of forms that are closely related but usually classified as four species: Llamas, Alpacas, Guanacos, and Vicunas.