The giraffe is a large African hoofed mammal belonging to the genus Giraffa. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes have been thought of as one species, Giraffa camelopardalis, with nine subspecies. Most recently, researchers proposed dividing them into four extant species due to new research into their mitochondrial and nuclear DNA, and individual species can be distinguished by their fur coat patterns. Seven other extinct species of Giraffa are known from the fossil record.
The okapi, also known as the forest giraffe, Congolese giraffe and zebra giraffe, is an artiodactyl mammal that is endemic to the northeast Democratic Republic of the Congo in central Africa. However, non-invasive genetic identification has suggested that a population has occurred south-west of the Congo River as well. It is the only species in the genus Okapia. Although the okapi has striped markings reminiscent of zebras, it is most closely related to the giraffe. The okapi and the giraffe are the only living members of the family Giraffidae.
The Giraffidae are a family of ruminant artiodactyl mammals that share a common ancestor with deer and bovids. This family, once a diverse group spread throughout Eurasia and Africa, presently comprises only two extant genera, the giraffe and the okapi. Both are confined to sub-Saharan Africa: the giraffe to the open savannas, and the okapi to the dense rainforest of the 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 ossicones.
Ancylotherium is an extinct genus of the family Chalicotheriidae, subfamily Schizotheriinae, endemic to Europe, Asia, and Africa during the Late Miocene-Early Pleistocene, existing for approximately 9.8 million years.
Sivatherium is an extinct genus of giraffid that ranged throughout Africa and Eurasia. The species Sivatherium giganteum is, by weight, one of the largest giraffids known, and also one of the largest ruminants of all time.
Ossicones are columnar or conical skin-covered bone structures on the heads of giraffes, male okapi, and some of their extinct relatives. Ossicones are distinguished from the superficially similar structures of horns and antlers by their unique development and a permanent covering of skin and fur.
Climacoceras is a genus of extinct artiodactyl ungulates that lived in Africa and Europe during the Miocene. The members of Climacoceras were related to giraffes, and the genus was formerly placed within the Giraffidae, but is now placed in the Climacoceratidae, a sister group within the superfamily Giraffoidea. Fossils of the two best known species of Climacoceras, C. africanus and C. gentryi, have both been found in Kenya. The animals measured about 1.5 m (4.9 ft) tall and had large ossicones resembling antlers. C. africanus had ossicones resembling tall, thorn-covered plant stems, while the ossicones of C. gentryi resembled thorny crescents.
Giraffokeryx is an extinct genus of medium-sized giraffids known from the Miocene of the Indian subcontinent and Eurasia. It is distinguished from other giraffids by the four ossicones on its head; one pair in front of the eyes on the anterior aspect of the frontal bone and the other behind the eyes in the frontoparietal region overhanging the temporal fossae. It has a brachydont dentition like in other giraffids and its legs and feet are of medium length. Giraffokeryx is considered monotypic by most authors, in the form of G. punjabiensis, but other species have been assigned to the genus:
Honanotherium is a genus of extinct giraffid from the late Miocene of Henan Province, China, and East Azerbaijan Province, northwestern Iran. It was closely related to Bohlinia and was once thought to be ancestral to the modern giraffe. The living animal would have resembled a modern giraffe, but was somewhat shorter, with more massive ossicones.
Bramatherium is an extinct genus of giraffids that ranged from India to Turkey in Asia. It is closely related to the larger Sivatherium.
Mitilanotherium is an extinct genus of giraffes from the Pliocene and Pleistocene of Europe.
The Palaeomerycidae is an extinct family of Neogene ruminants belonging to the infraorder Pecora. Palaeomerycids lived in Europe and Asia exclusively during the Miocene, coevolving with cervids, bovids, moschids, and tragulids there as part of a dramatic radiation of ruminants by the early Miocene.
Samotherium is an extinct genus of Giraffidae from the Miocene and Pliocene of Eurasia and Africa. Samotherium had two ossicones on its head, and long legs. The ossicones usually pointed upward, and were curved backwards, with males having larger, more curved ossicones, though in the Chinese species, S. sinense, the straight ossicones point laterally, not upwards. The genus is closely related to Shansitherium. Fossil evidence suggests that Samotherium had a rounded muzzle, which would suggest a grazing lifestyle and a habitat composed of grassland. One common predator of this animal was the Amphimachairodus.
Helladotherium is an extinct genus of sivatheriine giraffid from Europe, Africa, and Asia during the Miocene. The most complete skeleton is that of a female, based on a comparison with an intact female Sivatherium giganteum skull.
Injanatherium is an extinct genus of giraffids from the Miocene of Iraq, Saudi Arabia, and Pakistan. Species of Injanatherium had at least two pairs of long, wing-like ossicones that emanated laterally above the orbits.
Promephitis is an extinct genus of mephitid, of which several species have been described from the Miocene and early Pliocene of Europe and Asia.
Tragoportax is an extinct genus of bovid ungulate. It lived during the upper Miocene, and its fossils have been found in Europe, Asia and Africa. Tragoportax is sometimes considered to have been a close relative of the extant nilgai, though it may have formed its own subfamily, along with Miotragocerus.
Giraffomorpha is a clade of pecoran ruminants containing the superfamilies Palaeomerycoidea (Palaeomerycidae) and Giraffoidea, of which the giraffe and okapi of the Giraffidae are the only extant members of the once-diverse clade as a result of a decline in diversity after the Miocene as a result of declines in temperatures. The clade is defined by the presence of ossicones, suggesting that the feature was developed as a result of basal, related evolutions between the two superfamilies rather than as an instance of parallel evolution. Giraffomorpha is also characterized by a lack of articular fossettes (hollows) in metatarsal bones III-IV.
Sivatheriinae is a subfamily of giraffids characterized by their robust size, short limbs, and the presence of large complicated ossicones in males. These animals lived in Asia, Africa, and parts of Europe from the late Miocene and early Pleistocene.
Bramiscus is an extinct genus of giraffid artiodactyl ungulates from the Miocene Chinji and Dhok Pathan formations of Pakistan. The genus contains a single species, B. micros, known from several partial skeletons.
