{{Short description|Family of mammals}} {{Automatic taxobox | fossil_range = {{Fossil range|50|0}} Middle Eocene – Holocene | image = Camel seitlich trabend.jpg | image_caption = A Bactrian camel walking in snow | display_parents = 2 | taxon = Camelidae | authority = Gray, 1821 | type_genus = ''Camelus'' | subdivision_ranks = Subfamilies and genera | subdivision = *†''Palauchenia'' *†''Poebrodon'' *†''Poebrotherium'' *Camelinae *†Miolabinae *†Stenomylinae | range_map = Camelid Range.png | range_map_caption = Range of camelids, all species }}
'''Camelidae''' is a family of mammals belonging to the ungulate order Artiodactyla (even-toed ungulates) and the only living family in the suborder Tylopoda. The seven extant species of '''camelid''' are divided into two tribes, Camelini, including dromedary camels, Bactrian camels and wild Bactrian camels, and Lamini, including llamas, alpacas, vicuñas, and guanacos.
==Characteristics== thumb|Camelid feet lack functional hooves, with the toe bones being embedded in a broad, cutaneous pad.<ref name="Domestic" />
Camelids are large, strictly herbivorous animals with slender necks and long legs. They differ from ruminants in a number of ways.<ref name="Fowler, M.E. 2010">Fowler, M.E. (2010). ''Medicine and Surgery of Camelids'', Ames, Iowa: Wiley-Blackwell. Chapter 1 "General Biology and Evolution" addresses the fact that camelids (including camels and llamas) are not ruminants, pseudo-ruminants, or modified ruminants.</ref> Their dentition show traces of vestigial central incisors in the incisive bone, and the third incisors have developed into canine-like tusks. Camelids also have true canine teeth and tusk-like premolars, which are separated from the molars by a gap. As in ruminants, the upper incisors are largely absent and are replaced by a dental pad consisting of connective tissue covered with epithelium.<ref>{{Citation |last=Niehaus |first=Andrew |title=Tooth Root Abscess |date=2022 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780323910156000893 |work=Comparative Veterinary Anatomy |pages=1013–1019 |access-date=2023-10-29 |publisher=Elsevier |language=en |doi=10.1016/b978-0-323-91015-6.00089-3 |isbn=978-0-323-91015-6|url-access=subscription }}</ref> The musculature of the hind limbs differs from those of other ungulates in that the legs are attached to the body only at the top of the thigh, rather than attached by skin and muscle from the knee upwards. Because of this, camelids have to lie down by resting on their knees with their legs tucked underneath their bodies.<ref name="Domestic">{{cite book | author = Clutton-Brock, Juliet| title = A Natural History of Domesticated Mammals | year = 1987 | pages = 208 | publisher = Cambridge University Press | isbn = 978-0-521-34697-9}}</ref> They have three-chambered stomachs, rather than four-chambered ones; their upper lips are split in two, with each part separately mobile; and, uniquely among mammals, their red blood cells are elliptical.<ref name="Fowler, M.E. 2010"/> They also have a unique type of antibodies, which lack the light chain, in addition to the normal antibodies found in other mammals. These so-called heavy-chain antibodies are being used to develop single-domain antibodies with potential pharmaceutical applications.
Camelids do not have hooves; rather, they have two-toed feet with toenails and soft foot pads (Tylopoda is Greek for "padded foot"). Most of the weight of the animal rests on these tough, leathery sole pads. The South American camelids have adapted to the steep and rocky terrain by adjusting the pads on their toes to maintain grip.<ref name=EoM>{{cite book|editor= Macdonald, D.|author= Franklin, William|year= 1984|title= The Encyclopedia of Mammals|publisher= Facts on File|location= New York|pages= [https://archive.org/details/encyclopediaofma00mals_0/page/512 512–515]|isbn= 978-0-87196-871-5|url-access= registration|url= https://archive.org/details/encyclopediaofma00mals_0/page/512}}</ref> The surface area of camels' foot pads can increase with increasing velocity in order to reduce pressure on the feet and larger members of the camelid species will usually have larger pad area, which helps to distribute weight across the foot.<ref>{{Cite journal|last1=Clemente|first1=Christofer J.|last2=Dick|first2=Taylor J. M.|last3=Glen|first3=Christopher L.|last4=Panagiotopoulou|first4=Olga|date=2020-03-02|title=Biomechanical insights into the role of foot pads during locomotion in camelid species|url= |journal=Scientific Reports|language=en|volume=10|issue=1|pages=3856|doi=10.1038/s41598-020-60795-9|issn=2045-2322|pmc=7051995|pmid=32123239|bibcode=2020NatSR..10.3856C}}</ref> Many fossil camelids were unguligrade and probably hooved, in contrast to all living species.<ref name=MamEv>{{cite book|author1= Savage, RJG|author2= Long, MR|year= 1986|title= Mammal Evolution: an illustrated guide|publisher= Facts on File|location= New York|pages= [https://archive.org/details/mammalevolutioni0000sava/page/216 216–221]|isbn= 978-0-8160-1194-0|url= https://archive.org/details/mammalevolutioni0000sava/page/216}}</ref>
Camelids are behaviorally similar in many ways, including their walking gait, in which both legs on the same side are moved simultaneously. While running, camelids engage a unique "running pace gait" in which limbs on the same side move in the same pattern they walk, with both left legs moving and then both right, which ensures that the fore and hind limb will not collide while in fast motion. During this motion, all four limbs momentarily are off the ground at the same time.<ref>{{Cite journal|last1=Janis|first1=Christine M.|last2=Theodor|first2=Jessica M.|last3=Boisvert|first3=Bethany|date=2002-03-14|title=Locomotor evolution in camels revisited: a quantitative analysis of pedal anatomy and the acquisition of the pacing gait|url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282002%29022%5B0110%3ALEICRA%5D2.0.CO%3B2|journal=Journal of Vertebrate Paleontology|language=en|volume=22|issue=1|pages=110–121|doi=10.1671/0272-4634(2002)022[0110:LEICRA]2.0.CO;2|s2cid=86174860 |issn=0272-4634|url-access=subscription}}</ref> Consequently, camelids large enough for human beings to ride have a typical swaying motion.
Dromedary camels, bactrian camels, llamas, and alpacas are all induced ovulators.<ref name="Chen">{{cite journal|journal=J. Reprod. Fertil.|year=1985|volume=74|issue=2|pages=335–339|title=Semen-induced ovulation in the bactrian camel (Camelus bactrianus).|author=Chen, B.X.|author2=Yuen, Z.X.|author3=Pan, G.W.|name-list-style=amp|access-date=September 12, 2014|url=http://www.reproduction-online.org/content/74/2/335.full.pdf|doi=10.1530/jrf.0.0740335|pmid=3900379|doi-access=free}}</ref>
The three Afro-Asian camel species have developed extensive adaptations to their lives in harsh, near-waterless environments. Wild populations of the Bactrian camel are even able to drink brackish water, and some herds live in nuclear test areas.<ref>[https://web.archive.org/web/20021206012648/http://news.nationalgeographic.com/news/2002/11/1126_021205_cameltrek.html Wild Bactrian Camels Critically Endangered, Group Says] National Geographic, 3 December 2002</ref>
Comparative table of the seven extant species in the family Camelidae: {| class="wikitable" style="text-align:center;" |- ! Species ! Image ! Natural range ! Weight |- |colspan="10" align=center style="background-color:BurlyWood" |'''''Camelus''''' |- | Bactrian camel (''Camelus bactrianus'') | align="center" | 95x95px |Central and Inner Asia<br />(entirely domesticated) | {{convert|300|to|1000|kg|lbs|abbr=on}} |- | Dromedary<br />or<br />Arabian camel (''Camelus dromedarius'') | x75px | South Asia and Middle East<br />(entirely domesticated) | {{convert|300|to|600|kg|lbs|abbr=on}} |- | Wild Bactrian camel (''Camelus ferus'') | 100px | China and Mongolia | 300 to 820 kg (660 to 1,800 lb) |- |colspan="10" align=center style="background-color:BurlyWood" |'''''Lama''''' |- | Llama (''Lama glama'') | x75px | (domestic form of guanaco) | {{convert|130|to|200|kg|lbs|abbr=on}} |- | Guanaco (''Lama guanicoe'') | x75px | South America | about {{convert|90|to|120|kg|lbs|abbr=on}} |- | Alpaca (''Lama pacos'') | x75px | (domestic form of vicuña) | {{convert|48|to|84|kg|lbs|abbr=on}} |- | Vicuña (''Lama vicugna'') | x75px | South American Andes | {{convert|35|to|65|kg|lbs|abbr=on}} |}
==Evolution== {{cladogram |clades= {{clade |label1='''Camelid''' |1= {{clade |label1=Lamini |1= {{clade |label1=''Lama'' |1= {{clade |1=''L. glama'' |2=''L. guanicoe'' |3=''L. vicugna'' |4=''L. pacos'' }} }} |label2=Camelini |2= {{clade |label1=''Camelus'' |1= {{clade |1=''C. bactrianus'' |2=''C. dromedarius'' |3=''C. ferus'' }} |label2=†''Camelops'' |2= {{clade hidden |1=''C. kansanus'' |2=''C. hesternus'' |3=''C. minodokae'' }} }} }} }} |caption=A family tree indicating different species within the Camelidae family<ref>"Animal Diversity Web." ADW: Camelidae: CLASSIFICATION. N.p., n.d. Web. 09 June 2017.</ref> }} [[File:Global Camelid Distribution and Migration.svg|thumb|left|350px|A dymaxion map of the biogeographic distribution of Camelidae species: {{legend|#58DAFF|Tertiary distribution}} {{legend|#006CBF|Present-day distributions}} {{legend|#00EAC1|Introduced (feral) distributions}}
The yellow dot is the origin of the family Camelidae and the black arrows are the historic migration routes that explain the present-day distribution.]] Camelids are unusual in that their modern distribution is almost the inverse of their area of origin. Camelids first appeared very early in the evolution of the even-toed ungulates, around 50 to 40 million years ago during the middle Eocene,{{citation needed|date=May 2021}} in present-day North America. Among the earliest camelids was the rabbit-sized ''Protylopus'', which still had four toes on each foot. By the late Eocene, around 35 million years ago, camelids such as ''Poebrotherium'' had lost the two lateral toes, and were about the size of a modern goat.<ref name=MamEv/><ref>{{cite book |editor=Palmer, D.|year=1999 |title= The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|publisher= Marshall Editions|location=London|pages= 274–277|isbn= 978-1-84028-152-1}}</ref>
The family diversified and prospered, with the two living tribes, the Camelini and Lamini, diverging in the late early Miocene, about 17 million years ago, but remained restricted to North America until about 6 million years ago, when ''Paracamelus'' crossed the Bering land bridge into Eurasia, giving rise to the modern camels, and about 3–2 million years ago, when ''Hemiauchenia'' emigrated into South America (as part of the Great American Interchange), giving rise to the modern llamas.<ref>{{Cite journal |last=Meachen |first=Julie A. |date=2005-12-31 |title=A New Species of Hemiauchenia (Artiodactyla, Camelidae) from the Late Blancan of Florida |journal=Bulletin of the Florida Museum of Natural History |publisher=University Press of Florida |volume=45 |issue=4 |pages=435–448 |doi=10.58782/flmnh.stwk6834}}</ref> A population of ''Paracamelus'' continued living in North America and evolved into the high arctic camel, which survived until the middle Pleistocene.
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, and possibly as a result of changing environmental conditions after the last ice age, or a combination of these factors. Three species groups survived—the dromedary of northern Africa and southwest Asia; the Bactrian camel of central 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 vicuñas. Camelids were domesticated by early Andean peoples,<ref>{{Cite book |last=Moore |first=Katherine M. |chapter=Early Domesticated Camelids in the Andes |title=The Archaeology of Andean Pastoralism |editor-first=Jose M. |editor-last=Capriles |editor2-first=Nicholas |editor2-last=Tripcevich |publisher=University of New Mexico Press |year=2016 |isbn=978-0-8263-5702-1 }}</ref> and remain in use today.
Fossil camelids show a wider variety than their modern counterparts. One North American genus, ''Titanotylopus'', stood {{Convert|3.5|m|abbr=on}} at the shoulder, compared with about {{Convert|2.0|m|abbr=on}} for the largest modern camelids. Other extinct camelids included small, gazelle-like animals, such as ''Stenomylus''. Finally, a number of very tall, giraffe-like camelids were adapted to feeding on leaves from high trees, including such genera as ''Aepycamelus'' and ''Oxydactylus''.<ref name=MamEv/> The word Carnyx ({{pl.|Carnices}}) has been proposed as a generic common name for these giraffe-like camelids.<ref>{{Cite book |last=Lucas |title=The Cenozoic Biota of North Hastings |year=2025 |isbn=9798296779526 |pages=45}}</ref>
Whether the wild Bactrian camel (''Camelus ferus'') is a distinct species or a subspecies (''C. bactrianus ferus'') is still debated.<ref>{{Cite journal|last1=Cui|first1=Peng|last2=Ji|first2=Rimutu|last3=Ding|first3=Feng|last4=Qi|first4=Dan|last5=Gao|first5=Hongwei|last6=Meng|first6=He|last7=Yu|first7=Jun|last8=Hu|first8=Songnian|last9=Zhang|first9=Heping|date=2007-07-18|title=A complete mitochondrial genome sequence of the wild two-humped camel (''Camelus bactrianus ferus''): an evolutionary history of camelidae|journal=BMC Genomics|language=En|volume=8|issue=1|pages=241|doi=10.1186/1471-2164-8-241|issn=1471-2164|pmc=1939714|pmid=17640355 |doi-access=free }}</ref><ref name="Ji-2009">{{Cite journal|last1=Ji|first1=R.|last2=Cui|first2=P.|last3=Ding|first3=F.|last4=Geng|first4=J.|last5=Gao|first5=H.|last6=Zhang|first6=H.|last7=Yu|first7=J.|last8=Hu|first8=S.|last9=Meng|first9=H.|date=2009-08-01|title=Monophyletic origin of domestic bactrian camel (''Camelus bactrianus'') and its evolutionary relationship with the extant wild camel (''Camelus bactrianus ferus'')|journal=Animal Genetics|language=en|volume=40|issue=4|pages=377–382|doi=10.1111/j.1365-2052.2008.01848.x|issn=1365-2052|pmc=2721964|pmid=19292708 |bibcode=2009AnGen..40..377J }}</ref> The divergence date is 0.7 million years ago, long before the start of domestication.<ref name="Ji-2009" />
==Scientific classification== [[File:07. Camel Profile, near Silverton, NSW, 07.07.2007.jpg|thumb|A dromedary camel (''C. dromedarius'') in the Australian outback, near Silverton, New South Wales]] [[File:Vicunacrop.jpg|thumb|South American vicuña (''Lama vicugna'')]] '''Family Camelidae''' * †Subfamily Poebrotheriinae * †Subfamily Miolabinae * †Subfamily Stenomylinae * Subfamily Camelinae ** Tribe Lamini *** Genus: ''Lama'' **** Llama, ''Lama glama'' **** Guanaco, ''Lama guanicoe'' **** Alpaca, ''Lama pacos'' **** Vicuña, ''Lama vicugna'' *** Genus: ''Hemiauchenia'' **** †''Hemiauchenia macrocephala'' **** †''Hemiauchenia minima'' **** †''Hemiauchenia blancoensis'' **** †''Hemiauchenia vera'' **** †''Hemiauchenia paradoxa'' *** Genus ''Palaeolama'' **** †''Palaeolama mirifica'' ** Tribe Camelini *** Genus: ''Camelus'' **** Bactrian camel, ''Camelus bactrianus'' **** Dromedary, ''Camelus dromedarius'' **** Wild Bactrian camel, ''Camelus ferus'' **** †Greater Syrian camel, ''Camelus moreli'' **** †Lesser Syrian camel, ''Camelus concordieae'' **** †''Camelus sivalensis'' **** †''Camelus knoblochi'' ***Genus: ''Camelops'' **** †''Camelops hesternus'' ***Genus: ''Paracamelus'' **** †''Paracamelus gigas''
==Phylogeny==
{{clade |thickness=3 |label1=Camelid ancestor |color1=yellow |1= {{clade |thickness=3 |color=yellow |1= {{clade |thickness=3 |color=yellow |color1=yellow |barbegin1=lime |barend1=lime |barlabel1=Lamini |1= {{clade |thickness=3 |color=yellow |label1=''Hemiauchenia'' |sublabel1=(10.3 to 0.012 mya<ref>{{Cite web |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42528 |title=Paleobiology Database - ''Hemiauchenia'' basic info |access-date=2020-06-29 |archive-date=2021-02-13 |archive-url=https://web.archive.org/web/20210213061017/http://fossilworks.org/bridge.pl?action=taxonInfo&taxon_no=42528 |url-status=live }}</ref>) |color1=lime |barbegin1=green |barend1=green |barlabel1=''Lama'' |1= {{clade |thickness=3 |color=green |1=''Lama guanicoe'' |2=''Lama glama'' |3=''Lama pacos'' |4=''Lama vicugna'' }} |label2=''Palaeolama'' |sublabel2=(1.8 to 0.012 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42539 Paleobiology Database - ''Palaeolama'' basic info]</ref>) |color2=lime |2={{clade}} |color3=lime |barbegin3=green |barend3=green |barlabel3=''Vicugna'' |3= |label4=''Blancocamelus'' |sublabel4=(1.8 to 0.3 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=161797 Paleobiology Database - ''Blancocamelus'' basic info]</ref>) |4={{clade}} |label5=''Pleiolama'' |sublabel5=(10.3 to 2.588 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42545 Paleobiology Database - ''Pleiolama'' basic info]</ref>) |5={{clade}} }} |color2=yellow |barbegin2=orange |barend2=orange |barlabel2=Camelini |2= {{clade |thickness=3 |color=yellow |label1=''Camelops'' |sublabel1=(2.588 to 0.012 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42520 Paleobiology Database - ''Camelops'' basic info]</ref>) |1={{clade}} |label2=''Paracamelus'' |sublabel2=(11.608 to 0.781 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42541 Paleobiology Database - ''Paracamelus'' basic info]</ref><ref>{{Cite journal|last1=Geraads|first1=Denis|last2=Didier|first2=Gilles|last3=Barr|first3=Andrew|last4=Reed|first4=Denne|last5=Laurin|first5=Michel|date=April 2020|title=The fossil record of camelids demonstrates a late divergence between Bactrian camel and dromedary=Acta Palaeontologica Polonica|journal=Acta Palaeontologica Polonica|language=en|volume=65|issue=2|pages=251–260|doi=10.4202/app.00727.2020|issn=0567-7920|eissn=1732-2421|doi-access=free}}</ref>) |color2=orange |barbegin2=purple |barend2=purple |barlabel2=''Camelus'' |2= {{clade |thickness=3 |color=red |1=Bactrian camel |2=Dromedary |color2=purple }} |label3=''Procamelus'' |sublabel3=(15.97 to 5.332 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42549 Database - ''Procamelus'' basic info]</ref>) |color3=orange |3={{clade}} }} }} |label3=''Hesperocamelus'' |sublabel3=(20.43 to 15.97 mya<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=42529 Database - ''Hesperocamelus'' basic info]</ref>) |3={{clade}} }} }} {{legend|green|Endemic to South America}} {{legend|lime|Endemic to North and South America}} {{legend|yellow|Endemic to North America}} {{legend|red|Endemic to Asia}} {{legend|purple|Endemic to Asia and Africa}}
== Extinct genera== {| class=wikitable !Genus name !Epoch !Remarks |- |''Aepycamelus'' |Miocene |Tall, s-shaped neck, true padded camel feet |- |''Aguascalientia''<ref name=Prothero2023>{{cite journal |last1= Prothero |first1= D.R. |last2= Beatty |first2= B.L. |last3= Marriott |first3= K. |date= September 2023 |title= Systematics of the long-nosed Floridatraguline camels (Artiodactyla: Camelidae) |journal= Fossil Record |volume= 9 |issue= 94 |pages= 533–545 |doi= 10.1130/abs/2023AM-391561 |bibcode= 2023GSAA...5591561P |url= https://www.researchgate.net/publication/374331864 |access-date=18 December 2023}}</ref> |Earliest Miocene |A small, primitive, narrow-snouted floridatraguline camel from Mexico, Texas, and Panama |- |''Camelops'' |Pliocene-Pleistocene |Large, with true camel feet and hump. Status uncertain |- |''Eulamaops'' | Pleistocene |From South America |- |''Floridatragulus'' |Early Miocene |An unusual species of camel with a long snout |- |''Hemiauchenia'' | Miocene-Pleistocene |A North and South American lamine genus |- |''Megatylopus'' | Miocene-Early Pleistocene |Large camelid from North America |- |''Megacamelus'' |Miocene-Pleistocene |The largest species of camelid |- |''Michenia'' | Early-Middle Miocene | A cameline that existed for 10 million years in North America |- |''Oxydactylus'' |Early Miocene |The earliest member of the "giraffe camel" family |- |''Palaeolama'' |Pleistocene |A North and South American lamine genus |- |''Poebrotherium'' |Oligocene |This species of camel took the place of deer and antelope in the White River Badlands. |- |''Procamelus'' |Miocene |Ancestor of extinct ''Titanolypus'' and modern ''Camelus'' |- |''Protylopus'' |Late Eocene |Earliest member of the camelids |- |''Stenomylus'' |Early Miocene |Small, gazelle-like camel that lived in large herds on the Great Plains |- |''Stevenscamelus''<ref name=Prothero2023/> |Late Eocene |Long-snouted primitive relative of ''Floridatragulus'' |- |''Titanotylopus'' |Miocene-Pleistocene |Tall, humped, true camel feet |}
== International Year of Camelids == In October 2017 the United Nations declared 2024 to be the International Year of Camelids in order to show how camelids are important for food security, economics and culture for many pastoral communities.<ref>{{cite news|url=https://www.hindustantimes.com/world-news/why-un-has-declared-2024-the-international-year-of-camelids-101702829445404.html |title=Why UN has declared 2024 the International Year Of Camelids |author=Adarsh Kumar Gupta|work=Hindustan Times News}}</ref><ref>{{Cite web |title=Kingdom Launches International Year of Camelids (IYC 2024) |url=https://spa.gov.sa/ |access-date=2024-06-11 |website=spa.gov.sa |language=en}}</ref><ref>{{Cite web |title=UN Declares 2024 As Year Of Camelids. Here's Why |url=https://www.ndtv.com/world-news/un-declares-2024-as-international-year-of-camelids-heres-why-4690822 |access-date=2024-06-11 |website=NDTV.com}}</ref><ref>{{Cite web |title= International Year of Camelids (IYC) 2024 |url=https://www.fao.org/camelids-2024/en |access-date=2024-06-11 |website=Food and Agriculture Organization of the United Nations |language=en}}</ref>
==References== {{Reflist|2}}
==External links== {{Commons category|Camelidae}} {{Wikispecies|Camelidae}} * [https://web.archive.org/web/20070911010818/http://savci.upol.cz/gal/_20/camelidae.htm Pictures of camelid species]
{{Artiodactyla|T.}} {{Camelids}}
{{Taxonbar|from=Q135022}} {{Authority control}}
Category:Camelidae Category:Extant Lutetian first appearances Category:Mammal families Category:Taxa named by John Edward Gray Category:Tylopoda