Camels, together with their relatives the llama, alpaca, vicuna, and guanaco, are the only living members of a large group of animals that were once native to all continents except Australia. Now only two species of camel remain: the Arabian camel, which is bred in northern Africa and Arabia, and the bactrian camel, which is bred in central Asia.
The Arabian camel has a single rounded hump on its back. The bactrian camel may have either one or two conical humps on its back. Arabian camels specially bred for racing are called dromedaries. Arabian and bactrian camels are sometimes crossbred to produce single-humped offspring that are larger and sturdier than either parent. The wild camels that roam Central Asia today are believed to be descendants of domesticated bactrian camels that have run wild.
More about camels on this website: I Love Camels