Examine individual changes

'{{Short description|A family of mammals belonging to even-toed ungulates}} {{Automatic Taxobox | name = Giraffidae | fossil_range = {{Fossil range|20|0}}Early [[Miocene]] - recent | image = okapi.bristol.600pix.jpg | image_caption = An [[okapi]] in [[Bristol Zoo]], England | image2 = Giraffe Mikumi National Park.jpg | image2_caption = [[Masai giraffe]] (''G. c. tippelskirchi'') at the [[Mikumi National Park]], [[Tanzania]] | taxon = Giraffidae | authority = [[John Edward Gray|Gray]], 1821 | subdivision_ranks = Subfamilies | subdivision = * †[[Canthumerycinae]] * [[Giraffa|Giraffinae]] * †[[Sivatheriinae]] }} The '''Giraffidae''' are a [[family (biology)|family]] of [[ruminant]] [[artiodactyl]] mammals that share a common ancestor with [[cervid]]s and [[bovid]]s. This family, once a diverse group spread throughout [[Eurasia]] and Africa, presently comprises only two extant genera, the [[giraffe]] (one or more species of ''[[Giraffa]]'', depending on taxonomic interpretation) and the [[okapi]] (the only known species of ''[[Okapia]]''). Both are confined to [[sub-Saharan Africa]]: the giraffe to the open [[savanna]]s, and the okapi to the dense [[rainforest]] of the [[Democratic Republic of the Congo|Congo]]. The two genera look very different on first sight, but share a number of common features, including a long, dark-coloured tongue, lobed canine teeth, and horns covered in skin, called [[ossicone]]s. ==Taxonomy== {| class="wikitable" |- ! Image !! Genus !! Living species |- |[[File:Okapia johnstoni1.jpg|175px]]||''[[Okapia]]'' || *''[[Okapia johnstoni]]'' |- |[[File:Australia Zoo Giraffe-2 (17998331829).jpg|175px]]||''[[Giraffa]]'' || *One species taxonomy: ** ''[[Giraffa camelopardalis]]'' *Four species taxonomy: ** ''[[Giraffa camelopardalis]]'' ** ''[[Giraffa giraffa]]'' ** ''[[Giraffa reticulata]]'' ** ''[[Giraffa tippelskirchi]]'' |- |} ===Evolutionary background=== [[File:Shansitherium fuguensis.JPG|thumb|right|''[[Shansitherium]]'' and ''[[Palaeotragus]] microdon'', two giraffids from the Miocene of Asia]] The giraffids are [[ruminant]]s of the clade [[Pecora]]. Other extant pecorans are the families [[Antilocapridae]] ([[pronghorn]]s), [[Cervidae]] (deer), [[Moschidae]] ([[musk deer]]), and [[Bovidae]] ([[Bovini|cattle]], [[Caprinae|goats and sheep]], [[Alcelaphinae|wildebeests and allies]], and [[antelope]]s). The exact interrelationships among the pecorans have been debated, mainly focusing on the placement of Giraffidae, but a recent large-scale ruminant genome sequencing study suggests Antilocapridae are the sister taxon to Giraffidae.<ref name=RumiantPhylo2020>{{Cite journal | last1 = Chen | first1 = L. | last2 = Qiu | first2 = Q. | last3 = Jiang | first3 = Y. | last4 = Wang | first4 = K. | title = Large-scale ruminant genome sequencing provides insights into their evolution and distinct traits | doi = 10.1126/science.aav6202 | journal = Science | volume = 364 | issue = 6446 | pages = eaav6202| year = 2019 | pmid = 31221828| pmc = | bibcode = 2019Sci...364.6202C}}</ref> The ancestors of pronghorn diverged from the giraffids in the [[Early Miocene]].<ref name=RumiantPhylo2020/> This was in part of a relatively late mammal diversification following a climate change that transformed [[subtropical]] [[woodland]]s into open [[savannah]] [[grassland]]s. The fossil record of giraffids and their stem-relatives is quite intensive, with fossil of these taxa include [[Gelocidae]], [[Palaeomerycidae]], [[Prolibytherium|Prolibytheridae]], and [[Climacoceratidae]].<ref name="solounias2007">{{cite book | last1 = Solounias | first1 = N. | year = 2007 | chapter = Family Giraffidae | editor1-last = Prothero| editor1-first = D.R.| editor2-last = Foss | editor2-first = S.E. | title = The Evolution of Artiodactyls. | publisher = The Johns Hopkins University Press | pages = 257–277 |isbn =9780801887352}}</ref><ref name="HMW2011">{{cite book | last1 = Skinner | first1 = J.| last2 = Mitchell| first2 = G. | year = 2011 | chapter = Family Giraffidae (Giraffe and Okapi) | editor1-last = Wilson | editor1-first = D.E.| editor2-last = Mittermeier | editor2-first = R.A. | title = Handbook of the Mammals of the World – Volume II | publisher = Lynx Ediciones |location=Barcelona | pages = 788–802 |isbn = 978-84-96553-77-4}}</ref> It is thought the palaeomerycids is the ancestral group that given rise to the prolibytherids, climacoceratids and the giraffids, all three forming a clade of pecorans known as [[Giraffomorpha]].<ref name="solounias2007"/><ref name="Sánchez et al 2015">{{cite journal|last1=Sánchez|first1=Israel M.|last2=Cantalapiedra|first2=Juan L.|last3=Ríos|first3=María|last4=Quiralte|first4=Victoria|last5=Morales|first5=Jorge|title=Systematics and Evolution of the Miocene Three-Horned Palaeomerycid Ruminants (Mammalia, Cetartiodactyla)|journal=PLOS ONE|date=2015|volume=10|issue=12|pages=e0143034|doi=10.1371/journal.pone.0143034|pmid=26630174|pmc=4668073|bibcode=2015PLoSO..1043034S}}</ref> The relationship between the climacoceratids and giraffids is supported by the presence of a bilobed canine,<ref name="solounias2007"/> and have been postulated into two hypotheses. One is the climacoceratids were the ancestors of the [[Sivatheriinae|sivathere]]s, as both groups were large, deer-like [[Giraffoidea|giraffoid]]s with brancing antler-like [[ossicone]]s, while an extinct basal group of giraffoids, [[Canthumerycinae|canthumerycines]], evolved into the ancestors of Giraffidae.<ref name="HMW2011"/> Another more commonly supported hypothesis is climacoceratids were merely the sister clade to giraffids, with sivatheres being either basal giraffids<ref name="solounias2007"/> or descended from a lineage that also includes the okapi.<ref name=Ríosetal2017>{{Cite journal | last1 = Ríos | first1 = M. | last2 = Sánchez | first2 = I.M. | last3 = Morales | first3 = J. | title = A new giraffid (Mammalia, Ruminantia, Pecora) from the late Miocene of Spain, and the evolution of the sivathere-samothere lineage. | doi = 10.1371/journal.pone.0185378 | journal = PLOS ONE | volume = 12 | issue = 11 | pages = e0185378| year = 2017 | pmid = 29091914| pmc = 5665556| bibcode = 2017PLoSO..1285378R}}</ref> While the current range of giraffids today is in [[Africa]], the fossil record of the group has shown this family was once widespread throughout of [[Eurasia]].<ref name="solounias2007"/><ref name="HMW2011"/><ref name=Ríosetal2017/> Below is the phylogenetic relationships of giraffomorphs after Solounias (2007)<ref name="solounias2007"/>, Sánchez et al. (2015)<ref name="Sánchez et al 2015"/> and Ríos et al. (2017)<ref name=Ríosetal2017/>: {{clade| style=font-size:100%; line-height:100%; width:100% |label1=[[Giraffomorpha]] |1={{clade |1=†[[Palaeomerycidae]] |2={{clade |label1=[[Giraffoidea]] |1={{clade |1=†[[Prolibytherium|Prolibytheridae]] |2={{clade |1=†[[Climacoceratidae]] |2={{clade |label1=[[Giraffidae]] |1={{clade |1=†[[Canthumerycinae]]{{efn|A grade of giraffids.}} |2={{clade |1=†[[Giraffokerycinae]] |2={{clade |label1= |1={{clade |1=†[[Bohlininae]] |2=[[Giraffa|Giraffinae]]}} |label2= |2={{clade |1=†[[Palaeotraginae]] |2={{clade |1=[[Okapi|Okapiinae]] |2={{clade |1=†[[Samotheriinae]]{{efn|A paraphyletic grade of palaeotragines ancestral to Sivatheriinae.}} |2=†[[Sivatheriinae]]}}}}}}}}}}}}}}}}}}}}}}}} ===Classification=== [[Image:Helladotherium.jpg|thumb|right|Skeletal illustration of ''[[Helladotherium]]'', now extinct]] [[Image:Palaeotragus-Tianjin Natural History Museum.jpg|thumb|right|Skeletal mount of ''[[Palaeotragus]]'' on display at the [[Tianjin Natural History Museum]].]] [[Image:Shansitherium-Beijing Museum of Natural History.jpg|thumb|right|Skeletal mount of ''[[Shansitherium]] tafeli'' on display at the [[Beijing Museum of Natural History]].]] Below is the total taxonomy of valid extant and fossil taxa (as well as junior synonyms which are listed in the brackets). '''Family Giraffidae''' <small>J.E.Gray, 1821</small> * Basal extinct giraffids ** †''[[Csakvarotherium]]'' <small>Kretzoi, 1930</small> *** †''Csakvarotherium hungaricum'' <small>Kretzoi, 1930</small> ** †''[[Injanatherium]]'' <small>Heintz, Brunet & Sen, 1981</small> *** †''Injanatherium arabicum'' <small>Morales, Soria & Thomas, 1987</small> *** †''Injanatherium hazimi'' <small>Heintz, Brunet & Sen, 1981</small> ** †''[[Propalaeomeryx]]'' <small>Lydekker, 1883</small> [''[[Progiraffa]]'' <small>Pilgrim, 1908</small>] *** †''Propalaeomeryx sivalensis'' <small>Lydekker, 1883</small> [''Progiraffa exigua'' <small>Pilgrim, 1908</small>] ** †''[[Shansitherium]]'' <small>Killgus, 1922</small> [''Schansitherium'' <small>[''sic'']</small>] *** †''Shansitherium quadricornis'' <small>(Bohlin, 1926)</small> [''Palaeotragus quadricornis'' <small>Bohlin, 1926</small>] *** †''Shansitherium tafeli'' <small>Killgus, 1922</small> ** †''[[Umbrotherium]]'' <small>Abbazzi, Delfino, Gallai, Trebini & Rook, 2008</small> *** †''Umbrotherium azzarolii'' <small>Abbazzi, Delfino, Gallai, Trebini & Rook, 2008</small> * Subfamily †[[Canthumerycinae]] <small>Hamilton, 1978</small> ** †''[[Georgiomeryx]]'' <small>Paraskevaidis, 1940</small> *** †''Georgiomeryx georgalasi'' <small>Paraskevaidis, 1940</small> ** †''[[Canthumeryx]]'' <small>Hamilton 1973</small> [''[[Zarafa (genus)|Zarafa]]'' <small>Hamilton, 1973</small>] *** †''Canthumeryx sirtensis'' <small>Hamilton 1973</small> [''Zarafa zelteni'' <small>Hamilton, 1973</small>] * Subfamily [[Giraffe|Giraffinae]] <small>J.E.Gray, 1821</small> ** Tribe [[Giraffe|Giraffini]] <small>J.E.Gray, 1821</small> *** Subtribe [[Giraffe|Giraffina]] <small>J.E.Gray, 1821</small> **** ''[[Giraffe|Giraffa]]'' <small>Brisson, 1762</small> [''Camelopardalis'' <small>von Schreber, 1784</small> and ''Orasius'' <small>Oken, 1816</small>] ***** ''[[Giraffe|Giraffa camelopardalis]]'' super-complex <small>(Linnaeus, 1758)</small> ****** ''[[Southern giraffe|Giraffa giraffa]]'' complex <small>(von Schreber, 1784)</small> ******* ''[[Angolan giraffe|Giraffa angolensis]]'' <small>Lydekker, 1903</small> – Angolan giraffe ******* ''[[South African giraffe|Giraffa giraffa]]'' <small>(von Schreber, 1784)</small> – South African giraffe ******* ''[[Masai giraffe|Giraffa tippelskirchii]]'' complex <small>Matschie, 1898</small> ******* ''[[Rhodesian giraffe|Giraffa thornicrofti]]'' <small>Lydekker, 1911</small> – Rhodesian giraffe ******* ''[[Masai giraffe|Giraffa tippelskirchii]]'' <small>Matschie, 1898</small> – Masai giraffe ****** ''[[Reticulated giraffe|Giraffa reticulata]]'' <small>de Winton, 1899</small> – Reticulated giraffe ****** ''[[Northern giraffe|Giraffa camelopardalis]]'' complex <small>(Linnaeus, 1758)</small> ******* ''[[West African giraffe|Giraffa peralta]]'' <small>Thomas, 1898</small> – West African giraffe ******* ''[[Kordofan giraffe|Giraffa antiquorum]]'' <small>Jardine & Swainson, 1835</small> – Kordofan giraffe ******* ''[[Northern giraffe|Giraffa camelopardalis]]'' <small>(Linnaeus, 1758)</small> – Northern giraffe ******** ''[[Rothschild's giraffe|Giraffa camelopardalis rothschildi]]'' <small>Lydekker, 1903</small> – Rothschild's giraffe ******** ''[[Nubian giraffe|Giraffa camelopardalis camelopardalis]]'' <small>(Linnaeus, 1758)</small> – Nubian giraffe ***** †''[[Giraffa jumae]]'' <small>Leakey, 1967</small> ***** †''[[Giraffa priscilla]]'' <small>Pilgrim, 1911</small> ***** †''[[Giraffa punjabiensis]]'' <small>Pilgrim, 1911</small> ***** †''[[Giraffa pygmaea]]'' <small>Harris, 1976</small> ***** †''[[Giraffa sivalensis]]'' <small>(Falconer & Cautley, 1843)</small> [''Camelopardalis sivalensis'' <small>Falconer & Cautley, 1843</small> and ''Camelopardalis affinis'' <small>Falconer & Cautley, 1843</small>] ***** †''[[Giraffa stillei]]'' <small>(Dietrich, 1942)</small> [''Okapia stillei'' <small>Dietrich, 1942</small> and ''Giraffa gracilis'' <small>Arambourg, 1947</small>] *** Subtribe †[[Bohlinina]] <small>Solounias, 2007</small> **** †''[[Bohlinia]]'' <small>Matthew, 1929</small> ***** †''Bohlinia adoumi'' <small>Likius, Vignaud & Brunet, 2007</small> ***** †''Bohlinia attica'' <small>(Gaudry & Lartet, 1856)</small> [''Giraffa attica'' <small>(Gaudry & Lartet, 1856)</small> and ''Orasius attica'' <small>(Gaudry & Lartet, 1856)</small>] ***** †''Bohlinia nikitiae'' <small>Kostopoulos, Koliadimou & Koufos, 1996</small> **** †''[[Honanotherium]]'' <small>Bohlin, 1926</small> ***** †''Honanotherium bernori'' <small>Solounias & Danowitz, 2016</small> ***** †''Honanotherium schlosseri'' <small>(Pilgrim, 1911)</small> [''Giraffa schlosseri'' <small>Pilgrim, 1911</small>] ** Tribe [[Palaeotragini]] <small>Pilgrim, 1910</small> *** Subtribe †[[Palaeotragina]] <small>Pilgrim, 1910</small> **** †''[[Giraffokeryx]]'' <small>Pilgrim, 1910</small> ***** †''Giraffokeryx anatoliensis'' <small>Geraads & Aslan, 2003</small> ***** †''Giraffokeryx primaevus'' <small>(Churcher, 1970)</small> [''Palaeotragus primaevus'' <small>Churcher, 1970</small>; ''Samotherium africanum'' <small>Churcher, 1970</small> and ''Amotherium africanum'' <small>[''sic'']</small>] ***** †''Giraffokeryx punjabiensis'' <small>Pilgrim, 1910</small> **** †''[[Palaeogiraffa]]'' <small>Bonis & Bouvrain, 2003</small> ***** †''Palaeogiraffa macedoniae'' <small>(Geraads, 1989)</small> [''Decennatherium macedoniae'' <small>Geraads, 1989</small>] ***** †''Palaeogiraffa major'' <small>Bonis & Bouvrain, 2003</small> ***** †''Palaeogiraffa pamiri'' <small>(Ozansoy, 1965)</small> [''Samotherium pamiri'' <small>Ozansoy, 1965</small>] **** †''[[Palaeotragus]]'' <small>Gaudry, 1861</small> [''[[Achtiaria]]'' <small>Borissiak, 1914</small>; ''[[Macedonitherium]]'' <small>Sickenberg, 1967</small>; ''[[Mitilanotherium]]'' <small>Samson & Radulesco, 1966</small> and ''[[Sogdianotherium]]'' <small>Sharapov, 1974</small>] ***** †''Palaeotragus coelophrys'' <small>(Rodler & Weithofer, 1890)</small> [''Alcicephalus coelophrys'' <small>Rodler & Weithofer, 1890</small>] ***** †''Palaeotragus germaini'' <small>Arambourg, 1959</small> ***** †''Palaeotragus inexspectatus'' <small>(Samson & Radulesco, 1966)</small> [''Macedonitherium martinii'' <small>Sickenberg, 1967</small>; ''Mitilanotherium inexpectatum'' <small>Samson & Radulesco, 1966</small>; ''Mitilanotherium kuruksaense'' <small>(Sharapov, 1974)</small>; ''Mitilanotherium martinii'' <small>(Sickenberg, 1967)</small>; ''Palaeotragus priasovicus'' <small>Godina & Bajgusheva, 1985</small> and ''Sogdianotherium kuruksaense'' <small>Sharapov, 1974</small>] ***** †''Palaeotragus lavocanti'' <small>Heintz, 1976</small> ***** †''Palaeotragus robinsoni'' <small>Crusafont-Pairó, 1979</small> ***** †''Palaeotragus rouenii'' <small>Gaudry, 1861</small> [''Palaeotragus microdon'' <small>Koken, 1885</small>] ***** †''Palaeotragus tungurensis'' <small>Colbert, 1936</small> **** †''[[Samotherium]]'' <small>Forsyth Major, 1888</small> [''[[Alcicephalus]]'' <small>Rodler & Weithofer, 1890</small>; ''[[Chersenotherium]]'' <small>Alexajew, 1916</small> and ''[[Amotherium]]'' <small>[''sic'']</small>] ***** †''Samotherium boissieri'' <small>Forsyth Major, 1888</small> ***** †''Samotherium eminens'' <small>(Alexajew, 1916)</small> [''Chersenotherium eminens'' <small>Alexajew, 1916</small>] ***** †''Samotherium major'' <small>Bohlin, 1926</small> ***** †''Samotherium neumayri'' <small>(Rodler & Weithofer, 1890)</small> [''Alcicephalus neumayri'' <small>Rodler & Weithofer, 1890</small>] ***** †''Samotherium sinense'' <small>(Schlosser, 1903)</small> [''Alcicephalus sinense'' <small>Schlosser, 1903</small>] *** Subtribe [[Okapiina]] <small>Bohlin, 1926</small> **** †''[[Afrikanokeryx]]'' <small>Harris, Solounias & Geraads, 2010</small> ***** †''Afrikanokeryx leakeyi'' <small>Harris, Solounias & Geraads, 2010</small> **** ''[[Okapi|Okapia]]'' <small>Lankester, 1901</small> ***** ''[[Okapi|Okapia johnstoni]]'' <small>(P. L. Sclater, 1901)</small> – Okapi * †Subfamily [[Sivatheriinae]] <small>Bonaparte, 1850</small> ** †''[[Birgerbohlinia]]'' <small>Crusafont Pairó, 1952</small> *** †''Birgerbohlinia schaubi'' <small>Crusafont Pairó, 1952</small> ** †''[[Bramatherium]]'' <small>Falconer, 1845</small> [''[[Hydaspitherium]]'' <small>Lydekker, 1876</small>] *** †''Bramatherium giganteus'' <small>Khan & Sarwar, 2002</small> *** †''Bramatherium grande'' <small>(Lydekker, 1878)</small> [''Hydaspitherium grande'' <small>Lydekker, 1878</small>] *** †''Bramatherium magnum'' <small>(Pilgrim, 1910)</small> [''Hydaspitherium magnum'' <small>Pilgrim, 1910</small>] *** †''Bramatherium megacephalum'' <small>(Lydekker, 1876)</small> [''Hydaspitherium megacephalum'' <small>Lydekker, 1876</small>] *** †''Bramatherium perimense'' <small>Falconer, 1845</small> *** †''Bramatherium progressus'' <small>Khan, Sarwar & Khan, 1993</small> *** †''Bramatherium suchovi'' <small>Godina, 1977</small> ** †''[[Decennatherium]]'' <small>Crusafont Pairó, 1952</small> *** †''Decennatherium rex'' <small>Ríos, Sánchez & Morales, 2017</small> *** †''Decennatherium pachecoi'' <small>Crusafont Pairó, 1952</small> ** †''[[Helladotherium]]'' <small>Gaudry, 1860</small> *** †''Helladotherium duvernoyi'' <small>(Gaudry & Lartet, 1856)</small> [''Camelopardalis duvernoyi'' <small>Gaudry & Lartet, 1856</small>] ** †''[[Sivatherium]]'' <small>Falconer & Cautley, 1836</small> [''[[Griquatherium]]'' <small>Haughton, 1922</small>; ''[[Indratherium]]'' <small>Pilgrim, 1910</small>; ''[[Libytherium]]'' <small>Pomel, 1892</small> and ''[[Orangiatherium]]'' <small>van Hoepen, 1932</small>] *** †''Sivatherium giganteum'' <small>Falconer & Cautley, 1836</small> *** †''Sivatherium hendeyi'' <small>Harris, 1976</small> *** †''Sivatherium maurusium'' <small>(Pomel, 1892)</small> [''Libytherium maurusium'' <small>Pomel, 1892</small>; ''Griquatherium cingulatum'' <small>Haughton, 1922</small>; ''Helladotherium olduvaiense'' <small>Hopwood, 1934</small>; ''Sivatherium olduvaiense'' <small>(Hopwood, 1934)</small>; ''Libytherium olduvaiense'' <small>Hopwood, 1934</small> and ''Orangiatherium vanrhyni'' <small>van Hoepen, 1932</small>] ** †''[[Vishnutherium]]'' <small>Lydekker, 1876</small> *** †''Vishnutherium iravadicum'' <small>Lydekker 1876</small> ==Characteristics== [[File:Giraffes Mikumi National Park.jpg|thumb|left|Two giraffes]] The giraffe stands {{convert|5|–|6|m|abbr=on}} tall, with males taller than females. The giraffe and the okapi have characteristic long necks and long legs. Ossicones are present on males and females in the giraffe, but only on males in the okapi.<ref name=Dagg1971>{{Cite journal|author=Dagg, A. I.|authorlink=Anne Innis Dagg|year=1971|title=Giraffa camelopardalis|journal= Mammalian Species|volume=5|pages=1–8|url= http://www.science.smith.edu/msi/pdf/i0076-3519-005-01-0001.pdf|doi=10.2307/3503830|issue=5|jstor=3503830}}</ref> Giraffids share many common features with other ruminants. They have cloven hooves and [[cannon bone]]s, much like bovids, and a complex, four-chambered stomach. They have no upper [[incisor]]s or upper [[canine (tooth)|canines]], replacing them with a tough, horny pad. An especially long [[diastema (dentistry)|diastema]] is seen between the front and cheek teeth. The latter are [[molar (tooth)#Molars among species|selenodont]], adapted for grinding up tough plant matter.<ref name=Pellew>{{Cite book | last = Pellew | first = Robin | title = The Encyclopedia of Mammals | pages = [https://archive.org/details/encyclopediaofma00mals_0/page/534 534–541] | editor-last = MacDonald | editor-first = D. | year = 1984 | publisher = Facts on File | location = New York | isbn = 978-0-87196-871-5 | url-access = registration | url = https://archive.org/details/encyclopediaofma00mals_0/page/534 }}</ref> Like most other ruminants, the [[dentition|dental formula]] for giraffids is {{DentalFormula|upper=0.0.3.3|lower=3.1.3.3}}. Giraffids have prehensile tongues (specially adapted for grasping).<ref name=kingdon>{{cite book|last1=Kingdon|first1=Jonathan|title=Mammals of Africa.|date=2013|publisher=A. & C. Black|location=London|isbn=978-1-4081-2251-8|pages=95–115|edition=1st}}</ref> The extant giraffids, the forest-dwelling okapi and the savannah-living giraffe, have several features in common, including a pair of skin-covered horns, called ossicones, up to {{Convert|15|cm|abbr=on}} long (absent in female okapis); a long, black, prehensile tongue; lobed canine teeth; patterned coats acting as camouflage; and a back sloping towards the rear. The okapi's neck is long compared to most ruminants, but not nearly so long as the giraffe's. Male giraffes are the tallest of all mammals, their horns reach {{Convert|5.5|m|abbr=on}} above the ground and their shoulder {{Convert|3.3|m|abbr=on}}, whereas the okapi has a shoulder height of {{Convert|1.7|m|abbr=on}}.<ref name=grzimek/> ==Distribution== The two extant genera are now confined to [[sub-Saharan Africa]]. The okapi is restricted to a small range in the northern rainforest of the [[Democratic Republic of Congo]]. Although the range of the giraffe is considerably larger, it once covered an area twice the present size&nbsp;— all parts of Africa that could offer an arid and dry landscape furnished with trees.<ref name=grzimek/> ==Behavior== The social structure and behavior is markedly different in okapis and giraffes, but although little is known of the okapi's behavior in the wild, a few things are known to be present in both species:<ref name=grzimek>{{Cite book| last = Grzimek | first = Bernhard | authorlink = Bernhard Grzimek| title = Grzimek's Animal Life Encyclopedia, Vol 15, Mammals IV | edition = 2nd| editor1-last = Hutchins | editor1-first = Michael| editor2-last = Kleiman | editor2-first = Devra G| editor3-last = Geist | editor3-first = Valerius|display-editors = 3 | editor4-last = McDade | editor4-first = Melissa C| year = 2003 | publisher = Gale Group | location = Farmington Hills, MI| isbn = 978-0-7876-5362-0}}</ref> * They have an ambling gait similar to camels, with their weight supported alternately by their left and right legs, while their necks maintain balance. Giraffes can run up to {{Convert|60|kph|abbr=on}} this way and are documented to have covered {{Convert|1,500|km|abbr=on}} in the [[Sahel]] during the dry season. * The dominance hierarchy, which has been well-documented among giraffes, has also been seen among captive okapis. An adult giraffe head can weigh {{Convert|30|kg|abbr=on}}, and if necessary, male giraffes establish a hierarchy among themselves by swinging their heads at each other, horns first, a behavior known as "necking". A subordinate okapi signals submission by placing its head and neck on the ground. : Giraffes are sociable, whereas okapis live mainly solitary lives. Giraffes temporarily form herds of up to 20 individuals; these herds can be mixed or uniform groups of males and females, young and adults. Okapis are normally seen in mother-offspring pairs, although they occasionally gather around a prime food source. Giraffe are not territorial, but have ranges that can dramatically vary between&nbsp;— {{Convert|5|and|654|km2|abbr=on}}&nbsp;— depending on food availability, whereas okapis have individual ranges about {{Convert|2.5|-|5|km2|abbr=on}} in size. * Giraffes and okapis are normally silent, but both have a range of vocalizations, including coughing, snorting, moaning, hissing, and whistling. Giraffes have been suggested to be able to communicate using [[Infrasound|infrasonic]] sounds like elephants and blue whales. ==Notes== {{notelist}} ==References== {{Reflist|25em}} {{Artiodactyla|R.}} {{Taxonbar|from=Q186154}} [[Category:Even-toed ungulates]] [[Category:Giraffes| ]] [[Category:Mammal families]] [[Category:Extant Burdigalian first appearances]] [[Category:Taxa named by John Edward Gray]]'