Ungulates are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. Living ungulates are divided into two orders: the odd-toed ungulates (Perissodactyla) including horses, rhinoceroses, and tapirs; and even-toed ungulates (Artiodactyla) such as cattle, pigs, giraffes, camels, sheep, deer, and hippopotamuses. Cetaceans such as whales, dolphins, and porpoises are also classified as even-toed ungulates, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. Two other orders of ungulates, Notoungulata, and Litopterna, native to South America, became extinct at the end of the Pleistocene, around 12,000 years ago.
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including muntjac, elk (wapiti), red deer, and fallow deer; and the Capreolinae, including reindeer (caribou), white-tailed deer, roe deer, and moose. Male deer of all species, as well as female reindeer, grow and shed new antlers each year. In this, they differ from permanently horned antelope, which are part of a different family (Bovidae) within the same order of even-toed ungulates (Artiodactyla).
The even-toed ungulates are ungulates—hoofed animals—which bear weight equally on two of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on an odd number of the five toes. Another difference between the two is that many other even-toed ungulates digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do.
Antlers are extensions of an animal's skull found in members of the Cervidae (deer) family. Antlers are a single structure composed of bone, cartilage, fibrous tissue, skin, nerves, and blood vessels. They are generally found only on males, with the exception of reindeer/caribou. Antlers are shed and regrown each year and function primarily as objects of sexual attraction and as weapons.
The subfamily Caprinae, also sometimes referred to as the tribe Caprini, is part of the ruminant family Bovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine, or, more informally, a goat-antelope.
The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and caprines. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, the family Bovidae consists of 11 major subfamilies and thirteen major tribes. The family evolved 20 million years ago, in the early Miocene.
Moschidae is a family of pecoran even-toed ungulates, containing the musk deer (Moschus) and its extinct relatives. They are characterized by long 'saber teeth' instead of horns, antlers or ossicones, modest size and a lack of facial glands. The fossil record of the family extends back to the late Oligocene, around 28 million years ago. The group was abundant across Eurasia and North America during the Miocene, but afterwards declined to only the extant genus Moschus by the early Pleistocene.
Chevrotains, or mouse-deer, are diminutive, even-toed ungulates that make up the family Tragulidae, and are the only living members of the infraorder Tragulina. The 10 extant species are placed in three genera, but several species also are known only from fossils. The extant species are found in forests in South and Southeast Asia; a single species, the water chevrotain, is found in the rainforests of Central and West Africa. They are solitary, or live in loose groupings or pairs, and feed almost exclusively on plant material. Chevrotains are the smallest hoofed mammals in the world. The Asian species weigh between 0.7 and 8.0 kg, while the African chevrotain is considerably larger, at 7–16 kg (15–35 lb). With an average length of 45 cm (18 in) and an average height of 30 cm (12 in), the Java mouse-deer is the smallest surviving ungulate (hoofed) mammal, as well as the smallest artiodactyl. Despite their common name of "mouse deer", they are actually not true deer at all (Cervidae), but form a unique family of bovids closer in lineage to cattle or antelope.
Muntjacs, also known as the barking deer or rib-faced deer, are small deer of the genus Muntiacus native to South Asia and Southeast Asia. Muntjacs are thought to have begun appearing 15–35 million years ago, with remains found in Miocene deposits in France, Germany and Poland. Most species are listed as Least Concern or Data Deficient by the IUCN, although others such as the black muntjac, Bornean yellow muntjac, and giant muntjac are Vulnerable, Near Threatened, and Critically Endangered, respectively.
The Southern red muntjac is a deer species native to Southeast Asia. It is formely known as the Indian muntjac or the common muntjac before the species was taxonomically revised to represent only populations of Sunda and perhaps Malaysia. The other populations being attributed to this species are now attributed to Muntiacus vaginalis. Muntjacs are also referred to as barking deer. It is listed as Least Concern on the IUCN Red List.
The water deer is a small deer species native to China and Korea. Its prominent tusks, similar to those of musk deer, have led to both subspecies being colloquially named vampire deer in English-speaking areas to which they have been imported. It was first described to the Western world by Robert Swinhoe in 1870.
Pecora is an infraorder of even-toed hoofed mammals with ruminant digestion. Most members of Pecora have cranial appendages projecting from their frontal bones; only two extant genera lack them, Hydropotes and Moschus. The name “Pecora” comes from the Latin word pecus, which means “horned livestock”. Although most pecorans have cranial appendages, only some of these are properly called “horns”, and many scientists agree that these appendages did not arise from a common ancestor, but instead evolved independently on at least two occasions. Likewise, while Pecora as a group is supported by both molecular and morphological studies, morphological support for interrelationships between pecoran families is disputed.
The Siberian musk deer is a musk deer found in the mountain forests of Northeast Asia. It is most common in the taiga of southern Siberia, but is also found in parts of Mongolia, Inner Mongolia, Manchuria and the Korean peninsula.
The white-bellied musk deer or Himalayan musk deer is a musk deer species occurring in the Himalayas of Nepal, Bhutan, India, Pakistan and China. It is listed as endangered on the IUCN Red List because of overexploitation resulting in a probable serious population decline.
The black musk deer or dusky musk deer is a species of even-toed ungulate in the family Moschidae. It is found in Bhutan, China, India, Myanmar, and Nepal.
Micromeryx is an extinct genus of musk deer that lived during the Miocene epoch. Fossil remains were found in Europe and Asia. The earliest record (MN4) of the genus comes from the Sibnica 4 paleontological site near Rekovac in Serbia.
Rucervus is a genus of deer from India, Nepal, Indochina, and the Chinese island of Hainan. The only extant representatives, the barasingha or swamp deer and Eld's deer, are threatened by habitat loss and hunting; another species, Schomburgk’s deer, went extinct in 1938. Deer species found within the genus Rucervus are characterized by a specific antler structure, where the basal ramification is often supplemented with an additional small prong, and the middle tine is never present. The crown tines are inserted on the posterior side of the beam and may be bifurcated or fused into a small palmation.
Deer musk is a substance with a persistent odor, obtained from the caudal glands of the male musk deer.
The Gelocidae are an extinct group of hornless ruminantia that are estimated to have lived during the Eocene and Oligocene epochs, from 36 MYA to 6 MYA. The family generally includes extinct hornless ruminants which do not belong to similar families such as Moschidae or Tragulidae. Fossils of family Gelocidae have been discovered in Europe, Asia, Africa, and North America.
