A single specimen of the Roosevelt's muntjac or Roosevelt's barking deer (Muntiacus rooseveltorum) was presented to the Field Museum in 1929 following the Kelley-Roosevelts expedition organized by Theodore (Jnr) and Kermit Roosevelt. The specimen is slightly smaller than the common muntjac and DNA testing has shown it to be distinct from recently discovered muntjac species. It is a subspecies of Fea's muntjac, whose home range is mountains further northwest separated by lower land. However, without further evidence, the exact position of Roosevelt's muntjac cannot be stated. Berlin Zoo supposedly held this species between 1961 and 1972 (following an import from Northern Vietnam) but it could have been an Indian muntjac, subspecies annamensis. 
Roosevelt's muntjac was believed to have been extinct since 1929. However, there have been several recent claims to have rediscovered the species, from evidence including skulls owned by villagers in the Truong Son (Annamite) mountains of northern Laos and far northwestern Vietnam. More recently, photographs from a camera trap at Xuan Lien Nature Reserve in Vietnam appear to have identified two individuals. 
Eld's deer, also known as the thamin or brow-antlered deer, is an endangered species of deer endemic to South Asia.
The giant muntjac, sometimes referred to as the large-antlered muntjac, is a species of muntjac deer. It is the largest muntjac species and was discovered in 1994 in Vũ Quang, Hà Tĩnh Province of Vietnam and in central Laos. During inundation of the Nakai Reservoir in Khammouane Province of Laos for the Nam Theun 2 Multi-Purpose Project, 38 giant muntjac were captured, studied, and released into the adjacent Nakai-Nam Theun National Protected Area. Subsequent radio-tracking of a sample of these animals showed the relocation was successful. The species is also located in parts of eastern Cambodia, as well as the Trường Sơn Mountains.
The Truong Son muntjac or Annamite muntjac is a species of muntjac deer. It is one of the smallest muntjac species, at about 15 kg (33 lb), half the size of the Indian muntjac. It was discovered in the Truong Son mountain range in Vietnam in 1997.
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 leaf muntjac, leaf deer or Putao muntjac is a small species of muntjac. It was documented in 1997 by biologist Alan Rabinowitz during his field study in the isolated Naungmung Township in Myanmar. Rabinowitz discovered the species by examining the small carcass of a deer that he initially believed was the juvenile of another species; however, it proved to be the carcass of an adult female. He managed to obtain specimens, from which DNA analysis revealed a new cervid species. Local hunters knew of the species and called it the leaf deer because its body could be completely wrapped by a single large leaf. It is found in Myanmar and India.
The Indian muntjac or the common muntjac, also called the southern red muntjac and barking deer, is a deer species native to South and Southeast Asia. It is listed as Least Concern on the IUCN Red List. In popular local language, it is known as Kaakad or Kakad (काकड़)
The eastern elk is an extinct subspecies or distinct population of elk that inhabited the northern and eastern United States, and southern Canada. The last eastern elk was shot in Pennsylvania on September 1, 1877. The subspecies was declared extinct by the United States Fish and Wildlife Service in 1880. Another subspecies of elk, the Merriam's elk, also became extinct at roughly the same time.
Reeves's muntjac, also known as the Chinese muntjac, is a muntjac species found widely in southeastern China and Taiwan. It has also been introduced in Europe and Japan. It takes its name from John Reeves, a naturalist employed by the British East India Company in the 19th century.
The hairy-fronted muntjac or black muntjac is a type of deer currently found in Zhejiang, Anhui, Jiangxi and Fujian in southeastern China. It is considered to be endangered, possibly down to as few as 5–10,000 individuals spread over a wide area. Reports of hairy-fronted muntjacs from Burma result from considering the hairy-fronted muntjac and Gongshan muntjac as the same species. This suggestion is controversial. It is similar in size to the common muntjac.
The Gongshan muntjac is a species of muntjac living in the Gongshan mountains in northwestern Yunnan, southeast Tibet, Northeast India and northern Myanmar.
Indo-Burma is a biodiversity hotspot designated by Conservation International.
The Northern Indochina subtropical moist forests are a subtropical moist broadleaf forest ecoregion of northern Indochina, covering portions of Vietnam, Laos, Thailand, Myanmar, and China's Yunnan Province.
The wildlife of Vietnam is rich in flora and fauna as reflected by its unique biodiversity. Rare and endemic antelope-like animal, categorized under the bovine subfamily, was found in 1992, in Bạch Mã National Park. In the 1990s, three other large mammal species, the deer-like Truong Son muntjac, giant muntjac and Pu Hoat muntjac, were also discovered, the first two in the same park. Conservation protection and scientific studies of the ecology of Vietnam, particularly in the protected forest areas, have been given priority attention by the Government of Vietnam. Laws were enacted to set up Xuân Thủy Wetland National Park, four UNESCO Biosphere Reserves, and Hạ Long Bay and Phong Nha-Kẻ Bàng National Parks; the last two are also designated as UNESCO World Heritage Sites.
The Vietnam mouse-deer, also known as the silver-backed chevrotain, is an even-toed ungulate in the family Tragulidae known only from Vietnam. It was first described in 1910 by British zoologist Oldfield Thomas, who procured four specimens from Nha Trang in Annam. Little is known about its distribution and ecology. After 1910, the Vietnam mouse-deer was reported next in 1990 near Dak Rong and Buon Luoi in the Gia Lai Province. With increasing hunting pressure, habitat loss due to deforestation and no more reports of the species in the wild, the mouse-deer was feared to have gone extinct. The IUCN listed the species as Data Deficient in 2008. In 2019, a study confirmed the presence of the Vietnam mouse-deer in dry low-lying forests of southern Vietnam with camera trap evidence. The mouse-deer is characterised by a rough coat with a strange double-tone coloration unseen in other chevrotains; the front part of the body is reddish brown and contrasts strongly with the greyish posterior. It has big reddish brown ears, white and dark reddish brown marks on the throat.
The Sumatran muntjac is a subspecies of Indian muntjac in the deer family which can be the size of a large dog. It was discovered in 1914, but had not been sighted since 1930 until one was snared and freed from a hunter's snare in Kerinci Seblat National Park, Sumatra, Indonesia in 2002. Two other Sumatran muntjac have since been photographed in the park. The Sumatran muntjac was placed on the IUCN Red List in 2008, but was listed as Data Deficient, as taxonomic issues are still unresolved. The distribution of the taxon is also uncertain and may be more extensive than suggested. It is possible that some previous sightings of the common muntjac in Western Sumatra were the Sumatran muntjac.
The Pu Hoat muntjac is a species of muntjac only known from Pu Hoat region in Vietnam, which is bordering Laos. It is sometimes considered to be conspecific with Roosevelt's muntjac, and its habitat and behavior are likely to be similar.