The Past and Present Distributions of the Camelidae Family

Camelidae is a family that has its place to the Artiodactyla order which comprises three sub-orders: the ruminatia (Bovidae family), the suiforms (Suidae family) and tylopoda of which camelidae belong and are characterised by having a padded foot. The camelidae family is the only one under the sub-order Tylopoda and can be divided into two focal types (large and small camelids) and are distributed into the genera: Camelus, Lama and Vicugna.
The small camelids (Lamini) originated from the South American Andes Mountains and include four species, two of which are domesticated (llama and alpaca) and the others being wild (guanaco in the genus Lama and vicuna in the genus Vicugna). The large camelids (Camelini) are characterised two species, both domesticated being: the one-humped camel (Dromedary) found in the hot dry regions of northern Africa and eastern Asia and the two-humped camel (Bactrian) that lives in the cold steppes and deserts in Central Asia.
The camelidae family probably appeared in North America by the Oligocene period, 35 million years ago (Kadim, Maghoub, Faye, & Farouk, 2013) where they remained endemic up until late Miocene when they became extinct in North America about 5,000 years ago at the end of the last glacial period. The first representation of the camelidae family was the Poebrotherium.
The genus Hemiauchenia diverged into two distinctive genera in the early Pliocene that is: Lama and Peleolama, and then migrated to South America when the Isthmus of Pamana formed due to a subsidence in the ocean levels thus exposing land between North America and South America. The genus Peleolama did however become extinct at about the same time as camelids that remained in the North America while the genus Lama segmented into the genera Lama and Vicugna which gave rise to the South American camelids.
The direct ancestor of the Dromedary and Bactrian camels, Paracamelus had dispersed during the Pleistocene epoch by way of Alaska to Eurasia through the Bering Strait land bridge and quickly colonized the dry zone in the Northern Hemisphere. According to (Kadim, Maghoub, Faye, & Farouk, 2013) a direct ancestor known as Camelus thomasi was present over much of Europe and Asia. Camelus dromedarius divided from the northern branch of Camelini and dispersed across Arabia and progressed into Africa. Camelus dromedarius stretched from the Atlantic to northern India but it had been extinct in the African continent. It was introduced again into Africa after being domesticated.

References
KADIM, I.T., MAGHOUB, O., FAYE, B., & FAROUK, M. (Eds.). 2013. Camel Meat and Meat Products. CAB International, United Kingdom.
HICKMAN, V.B., ROBERTS, L.S. 2011. Integrated Principles of Zoology, 15th edn, pp. 806. McGraw-Hill, New York.
MEACHEN, J.A. 2003. A new species of Hemiauchenia (Camelidae; Lamini) from the plio-pleistocene of Florida. M.Sc. thesis, University of Florida, Florida, United States of America.

.