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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,[1][2] but several species also are known only from fossils.[3] 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.[4] They are solitary, or live in loose groupings or pairs, and feed almost exclusively on plant material.[4] Chevrotains are the smallest hoofed mammals in the world. The Asian species weigh between Template:Convert, while the African chevrotain is considerably larger, at Template:Convert.[5] With an average length of Template:Convert and an average height of Template:Convert, the Java mouse-deer is the smallest surviving ungulate (hoofed) mammal, as well as the smallest artiodactyl (even-toed ungulate).[6] Despite their common name of "mouse deer", they are not closely related to true deer.
In November 2019, conservation scientists announced that they had photographed silver-backed chevrotains (Tragulus versicolor) in a Vietnamese forest for the first time since the last confirmed sightings in 1990.[7][8][9]
Etymology
The word "chevrotain" comes from the Middle French word chevrot (kid or fawn), derived from chèvre (goat).[10]
The single African species is consistently known as "chevrotain".[1][4][11] The names "chevrotain" and "mouse-deer" have been used interchangeably among the Asian species,[4][12][13][14] though recent authorities typically have preferred chevrotain for the species in the genus Moschiola and mouse-deer for the species in the genus Tragulus.[1] Consequently, all species with pale-spotted or -striped upper parts are known as "chevrotain" and without are known as "mouse-deer".
The Telugu name for the Indian spotted chevrotain is jarini pandi, which literally means "a deer and a pig".Template:Citation needed In Kannada, it is called barka (ಬರ್ಕ), in Malayalam, it is called Template:Lang kūramān, and the Konkani name for it is barinka. The Tamil term is Template:Lang sarukumāṉ "leaf-pile deer". The Sinhala name Template:Transl roughly translates to "mouse-like deer". This was used in the scientific name of the Sri Lankan spotted chevrotain, M. meminna.
Biology
The family was widespread and successful from the Oligocene (34 million years ago) through the Miocene (about 5 million years ago), but has remained almost unchanged over that time and remains as an example of primitive ruminant form. They have four-chambered stomachs to ferment tough plant foods, but the third chamber is poorly developed. Though most species feed exclusively on plant material, the water chevrotain occasionally takes insects and crabs or scavenges meat and fish.[15] Like other ruminants, they lack upper incisors. They give birth to only a single young.
In other respects, however, they have primitive features, closer to nonruminants such as pigs. All species in the family lack antlers and horns, but both sexes have elongated canine teeth. These are especially prominent in males, where they project out on either side of the lower jaw, and are used in fights.[4] Their legs are short and thin, which leave them lacking in agility, but also helps to maintain a smaller profile to aid in running through the dense foliage of their environments. Other pig-like features include the presence of four toes on each foot, the absence of facial scent glands, premolars with sharp crowns,[16] and the form of their sexual behaviour and copulation.[17][16]
They are solitary or live in pairs.[4] The young are weaned at three months of age, and reach sexual maturity between 5 and 10 months, depending on species. Parental care is relatively limited. Although they lack the types of scent glands found in most other ruminants, they do possess a chin gland for marking each other as mates or antagonists, and, in the case of the water chevrotain, anal and preputial glands for marking territory. Their territories are relatively small, on the order of Template:Convert, but neighbors generally ignore each other, rather than compete aggressively.[16]
Some of the species show a remarkable affinity with water, often remaining submerged for prolonged periods to evade predators or other unwelcome intrusions. This has also lent support to the idea that whales evolved from water-loving creatures that looked like small deer.[18][19]
Taxonomy
Tragulidae's placement within Artiodactyla can be represented in the following cladogram:[20][21][22][23][24]
Traditionally, only four extant species were recognized in the family Tragulidae.[4] In 2004, T. nigricans and T. versicolor were split from T. napu, and T. kanchil and T. williamsoni were split from T. javanicus.[25] In 2005, M. indica and M. kathygre were split from M. meminna.[2] With these changes, the 10 extant species are:
- Family Tragulidae
- Genus Hyemoschus
- Water chevrotain, Hyemoschus aquaticus
- Genus Moschiola
- Indian spotted chevrotain, Moschiola indica
- Sri Lankan spotted chevrotain, Moschiola meminna
- Yellow-striped chevrotain, Moschiola kathygre
- Genus Tragulus
- Java mouse-deer, Tragulus javanicus
- Lesser mouse-deer or kanchil, Tragulus kanchil
- Greater mouse-deer, Tragulus napu
- Philippine mouse-deer, Tragulus nigricans
- Vietnam mouse-deer, Tragulus versicolor
- Williamson's mouse-deer, Tragulus williamsoni
- Genus Hyemoschus
Ancient chevrotains
The Hypertragulidae were closely related to the Tragulidae.
The six extinct chevrotain genera[3] include:
- Genus Dorcatherium
- Genus Dorcabune
- Genus Afrotragulus Sánchez, Quiralte, Morales and Pickford, 2010 [27]
- Afrotragulus moruorotensis (previously "Dorcatherium" moruorotensis Pickford, 2001) (early Miocene) from Moruorot, Kenya
- Afrotragulus parvus (previously "D." parvus Withworth 1958) (early Miocene) from Rusinga Island, Kenya
- Genus Siamotragulus
- Siamotragulus sanyathanai Thomas, Ginsburg, Hintong and Suteethorn, 1990 (middle Miocene) from Lampang, Thailand
- Siamotragulus haripounchai Mein and Ginsburg, 1997 (Miocene) from Lamphun, Thailand
- Genus Yunnanotherium
- Genus Archaeotragulus[28]
- Archaeotragulus krabiensis Metais, Chaimanee, Jaeger and Ducrocq, 2001 (late Eocene) from Krabi, Thailand
The extinct chevrotains might also include[29][30]
- Genus Krabitherium
- Krabitherium waileki Metais, Chaimanee, Jaeger and Ducrocq, 2007 (late Eocene) from Krabi, Thailand[31]
- Genus Nalameryx
Footnotes
References
- ↑ 1.0 1.1 1.2 Template:MSW3
- ↑ 2.0 2.1 Intraspecific variation in Moschiola, the Indian chevrotain. The Raffles Bulletin of Zoology({Template:Year).
- ↑ 3.0 3.1 Lower dentition of Dorcatherium majus (Tragulidae, Mammalia) in the Lower and Middle Siwaliks (Miocene) of Pakistan. Tur. J. Zool.({Template:Year).
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Walker's Mammals of the World{{#if:|, {{{last}}}}. Johns Hopkins University Press(1999)
- ↑ Hyemoschus aquaticus. Ultimate Ungulate. Retrieved 12 October 2010.
- ↑ Unique pits on the erythrocytes of the lesser mouse-deer, Tragulus javanicus. Journal of Anatomy({Template:Year).
- ↑ Silver-Backed Chevrotain, with Fangs and Hooves, Photographed In Wild for First Time. NPR. NPR.org(11 November 2019). Retrieved 12 November 2019.
- ↑ Camera-trap evidence that the silver-backed chevrotain Tragulus versicolor remains in the wild in Vietnam(11 November 2019). Retrieved 12 November 2019.
- ↑ Tiny deer-like animal spotted after 25 years. CNN(11 Nov 2019).
- ↑ Template:Cite Merriam-Webster
- ↑ Template:Cite iucn
- ↑ Template:Cite iucn
- ↑ Template:Cite iucn
- ↑ Template:Cite iucn
- ↑ The Kingdon Field Guide to African Mammals{{#if:|, {{{last}}}}. Academic Press(1997). ISBN 0-12-408355-2
- ↑ 16.0 16.1 16.2 The Encyclopedia of Mammals{{#if:|, {{{last}}}}. Facts on File(1984). ISBN 978-0-87196-871-5
- ↑ Deer of the World: Their Evolution, Behaviour, and Ecology{{#if:|, {{{last}}}}. Stackpole Books(1998). ISBN 978-0-8117-0496-0
- ↑ Aquatic deer and ancient whales. BBC News(2009-07-07). Retrieved 2010-03-26.
- ↑ Aquatic escape behaviour in mouse-deer provides insight into tragulid evolution. Mammalian Biology({Template:Date).
- ↑ A higher-level MRP supertree of placental mammals. BMC Evol Biol({Template:Year).
- ↑ The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals. Science({Template:Year).
- ↑ Resolving conflict in eutherian mammal phylogeny using phylogenomics and the multispecies coalescent model. Proceedings of the National Academy of Sciences({Template:Year).
- ↑ Phylogenomic datasets provide both precision and accuracy in estimating the timescale of placental mammal phylogeny. Proceedings of the Royal Society B: Biological Sciences({Template:Year).
- ↑ Inferring the mammal tree: Species-level sets of phylogenies for questions in ecology, evolution, and conservation. PLOS Biology({Template:Year).(see e.g. Fig S10)
- ↑ A taxonomic revision of the Tragulus mouse-deer. Zoological Journal of the Linnean Society({Template:Year).
- ↑ Über die Sichtung und Bearbeitung der jungtertiären Säugetierreste aus dem Hausruck und Kobernaußerwald (O.Ö.). Verh. Geol. B.-A.({Template:Year).
- ↑ A new genus of tragulid ruminant from the early Miocene of Kenya. Acta Palaeontologica Polonica({Template:Year).
- ↑ New remains of primitive ruminants from Thailand: Evidence of the early evolution of the Ruminantia in Asia. Zoologica Scripta({Template:Year).
- ↑ Mammalogy{{#if:|, {{{last}}}}(2011-04-21). ISBN 978-0-7637-6299-5
- ↑ A new genus of Tragulid ruminant from the Early Miocene of Kenya. Acta Palaeontologica Polonica({Template:Year).
- ↑ Krabitherium. Paleobiology Database (Paleodb.org). Retrieved 2013-01-18.
- ↑ Mennecart, B., Wazir, W.A., Sehgal, R.K., Patnaik, R., Singh, N.P., Kumar, N. and Nanda, A.C., 2021. New remains of Nalamaeryx (Tragulidae, Mammalia) from the Ladakh Himalaya and their phylogenetical and palaeoenvironmental implications. Historical Biology, pp.1-9.https://doi.org/10.1080/08912963.2021.2014479