Editing Okapi (section)

===Evolution===
[[File:Okapi Giraffe Neck.png|thumb|upright|Despite the vast difference in neck length, the okapi (left) and the giraffe (right) both have seven [[cervical vertebrae]] (as do all mammals except for manatees and sloths).]]
The earliest members of the Giraffidae first appeared in the early [[Miocene]] in Africa, having diverged from the superficially deer-like [[Climacoceratidae|climacoceratids]]. Giraffids spread into Europe and Asia by the middle Miocene in a first [[Radiation (biology)|radiation]]. Another radiation began in the [[Pliocene]], but was terminated by a decline in diversity in the [[Pleistocene]].<ref name=finlayson>{{cite book|last1=Finlayson|first1=Clive|title=Neanderthals and Modern Humans : An Ecological and Evolutionary Perspective|date=2009|publisher=Cambridge University Press|location=Cambridge|isbn=978-0521121002|page=25|edition=Digitally printed}}</ref> Several important primitive giraffids existed more or less contemporaneously in the Miocene (23–10 million years ago), including ''[[Canthumeryx]]'', ''[[Giraffokeryx]]'', ''[[Palaeotragus]]'', and ''[[Samotherium]]''. According to palaeontologist and author Kathleen Hunt, ''Samotherium'' split into ''Okapia'' (18 million years ago) and ''Giraffa'' (12 million years ago).<ref>{{cite web|author=Hunt, Kathleen|title=Transitional Vertebrate Fossils FAQ Part 2C|publisher=TalkOrigins|url=http://www.talkorigins.org/faqs/faq-transitional/part2c.html#arti|access-date=28 April 2015}}</ref> However, J. D. Skinner argued that ''Canthumeryx'' gave rise to the okapi and giraffe through the latter three genera and that the okapi is the extant form of ''Palaeotragus''.<ref>{{cite journal |last1=Mitchell |first1=G. |last2=Skinner |first2=J. D. |title=On the origin, evolution and phylogeny of giraffes Giraffa camelopardalis |journal=Transactions of the Royal Society of South Africa |volume=58 |issue=1 |year=2003 |doi=10.1080/00359190309519935 |pages=51–73|bibcode=2003TRSSA..58...51M |s2cid=6522531 }}</ref> The okapi is sometimes referred to as a [[living fossil]], as it has existed as a species over a long geological time period, and morphologically resembles more primitive forms (e.g. ''Samotherium'').<ref name=prothero/><ref name="auto1">{{cite news |url=https://news.google.com/newspapers?nid=1499&dat=19570624&id=wAMkAAAAIBAJ&pg=6731,2170969 |title=Why Is the Okapi Called a Living Fossil |newspaper=The Milwaukee Journal |date=24 June 1954 }}{{Dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

In 2016, a genetic study found that the common ancestor of giraffe and okapi lived about 11.5&nbsp;million years ago.<ref>{{cite journal |last1=Agaba |first1=M. |last2=Ishengoma |first2=E. |last3=Miller |first3=W. C. |last4=McGrath |first4=B. C. |last5=Hudson |first5=C. N. |last6=Bedoya Reina |first6=O. C. |last7=Ratan |first7=A. |last8=Burhans |first8=R. |last9=Chikhi |first9=R. |last10=Medvedev |first10=P. |last11=Praul |first11=C. A. |last12=Wu-Cavener |first12=L. |last13=Wood |first13=B. |last14=Robertson |first14=H. |last15=Penfold |first15=L. |last16=Cavener |first16=D. R. |title=Giraffe genome sequence reveals clues to its unique morphology and physiology |journal=[[Nature (journal)|Nature]] |date=May 2016 |volume=7 |pages=11519 |doi=10.1038/ncomms11519 |doi-access=free |pmid=27187213 |pmc=4873664|bibcode=2016NatCo...711519A }}</ref>