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 Artiodactyla order. Other suborders of Artiodactyla include pigs, peccaries and hippos (suborder Suidae) and the extraordinarily successful and diverse suborder Ruminantia (which includes cattle, goats, antelope and many others).

Camelids tend to be large and are strictly herbivorous. Camelids differ from 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 red blood cells. They have long legs that, because they lack tensor skin to bridge between thigh and body, look longer still. They do not have hooves, rather a two-toed foot with toenails and a soft footpad (Tylopoda is Latin for "padded foot"). The main weight of the animal is borne by these 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 camel species have developed extensive adaptations to fit them to life in harsh, near-waterless environments. Wild populations of the bactrian camel have even adapted to drink brackish water, and some herds live in nuclear test areas. 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 Eocene, in present-day North America. 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 Asia, 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.

Scientific classification

• ORDER ARTIODACTYLA
  • Suborder Suina
    • Family Suidae: pigs
    • Family Hippopotamidae: hippos
    • Family Tayassuidae: peccaries
  • Suborder Tylopoda
    • Family Camelidae
      • Genus: Lama
        • Llama, Lama glama
        • Guanaco, Lama guanicoe
      • Genus: Vicugna
        • Vicuna, Vicugna vicugna
        • Alpaca, Vicugna pacos (previously categorized in genus Lama)
      • Genus: Camelus
        • Dromedary, Camelus dromedarius
        • Bactrian Camel, Camelus bactrianus
  • Suborder Ruminantia
    • Family Tragulidae: chevrotains.
    • Family Moschidae: musk deer
    • Family Cervidae: deer.
    • Family Giraffidae: Giraffe and Okapi.
    • Family Antilocapridae: Pronghorn.
    • Family Bovidae: cattle, goats, sheep, and antelope.

Extinct genera of camelids

External links

• Pictures of camelid species

Camelids

Camèlid | Kameler og lamaer | Schwielensohler Kameledoj | Camélido | شترسانان | Camélidés | גמליים | Camelidae | Camelidae | ラクダ科 Kemelachtege | Camelidae Kameldyr | Wielbłądowate | Camelidae | Верблюдовые | Kameldjur | 駱駝科