Chevrotains, or mouse-deer, are small, even-toed ungulates that make up the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Tragulidae, and are the only living members of the

infraorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classific ...

Tragulina. The 10

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

species are placed in three genera, but several species also are known only from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s. 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 West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

. 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. 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 , while the African chevrotain is considerably larger, at . With an average length of and an average height of , the Java mouse-deer is the smallest surviving ungulate (hoofed) mammal, as well as the smallest artiodactyl (even-toed ungulate). Despite their common name of "mouse deer", they are not closely related to true deer.

Etymology

The word "chevrotain" comes from the Middle French word ''chevrot'' (kid or fawn), derived from ''chèvre'' (goat). The single African species is consistently known as "chevrotain". The names "chevrotain" and "mouse-deer" have been used interchangeably among the Asian species, though recent authorities typically have preferred chevrotain for the species in the genus '' Moschiola'' and mouse-deer for the species in the genus '' Tragulus''. 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". The Tamil term is ''sarukumāṉ'' "leaf-pile deer". The Sinhala name 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 The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

(34 million years ago) through the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

(about 5 million years ago), but has remained almost unchanged over that time and remains as an example of an archaic

ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...

type. They have four-chambered stomachs to ferment tough plant foods, but the third chamber is poorly developed. Unlike other artiodactyls, they lack an carotid rete, and so cannot heat exchange cool blood entering their brains, a thermoregulatory innovation that allows other artiodactyls to exploit hot arid habitats. Though most species feed exclusively on plant material, the water chevrotain occasionally takes insects and crabs or scavenges meat and fish. 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. 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,

premolar The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

s with sharp crowns, and the form of their sexual behaviour and copulation. They are solitary or live in pairs. 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 Preputial glands are exocrine glands in the prepuce in front of the penis. They occur in many mammals, including canids, mice, ferrets, rhinoceroses, and even-toed ungulates and produce pheromones. The preputial glands of female animals are so ...

for marking territory. Their territories are relatively small, on the order of , but neighbors generally ignore each other, rather than compete aggressively. 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.

Taxonomy

Tragulidae's placement within

Artiodactyla Artiodactyls are placental mammals belonging to the order (biology), order Artiodactyla ( , ). Typically, they are ungulates which bear weight equally on two (an even number) of their five toes (the third and fourth, often in the form of a hoof ...

can be represented in the following

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

:(see e.g. Fig S10) Traditionally, only four

species were recognized in the family Tragulidae. In 2004, ''T. nigricans'' and ''T. versicolor'' were split from ''T. napu'', and ''T. kanchil'' and ''T. williamsoni'' were split from ''T. javanicus''. In 2005, ''M. indica'' and ''M. kathygre'' were split from ''M. meminna''. 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''

Ancient chevrotains

The Hypertragulidae were closely related to the Tragulidae. The six extinct chevrotain genera include: *Genus '' Dorcatherium'' **''Dorcatherium minus'' from

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

**''Dorcatherium majus'' from

**''Dorcatherium naui'', from

Central Europe Central Europe is a geographical region of Europe between Eastern Europe, Eastern, Southern Europe, Southern, Western Europe, Western and Northern Europe, Northern Europe. Central Europe is known for its cultural diversity; however, countries in ...

*Genus '' Dorcabune'' **''Dorcabune anthracotherioides'' from

**''Dorcabune nagrii'' from

*Genus '' Afrotragulus'' Sánchez, Quiralte, Morales and Pickford, 2010 ** ''Afrotragulus moruorotensis'' (previously ''"Dorcatherium" moruorotensis'' Pickford, 2001) (early

) from Moruorot,

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

** ''Afrotragulus parvus'' (previously ''"D." parvus'' Withworth 1958) (early

) from Rusinga Island,

*Genus '' Siamotragulus'' **''Siamotragulus sanyathanai'' Thomas, Ginsburg, Hintong and Suteethorn, 1990 (middle

) from Lampang,

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

**''Siamotragulus haripounchai'' Mein and Ginsburg, 1997 (

) from Lamphun,

*Genus '' Yunnanotherium'' *Genus '' Archaeotragulus'' **''Archaeotragulus krabiensis'' Metais, Chaimanee, Jaeger and Ducrocq, 2001 (late

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

) from Krabi,

The extinct chevrotains might also include *Genus '' Krabitherium'' **''Krabitherium waileki'' Metais, Chaimanee, Jaeger and Ducrocq, 2007 (late

) from Krabi,

*Genus '' Nalameryx'' **''Nalameryx savagei'' **''Nalameryx sulaimani''

Mythology

According to the '' Malay Annals'', King Parameswara, seeking a place to found a new city, came to a place where he saw a mouse deer (''kancil'' in Malay) kicking his hunting dog into the

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

. He thought this boded well, remarking, 'this place is excellent, even the mouse deer is formidable; it is best that we establish a kingdom here'. He then founded there the city of Malacca. In memory of this founding legend, the coat of arms of Malacca depicts two mouse deer. The mouse deer or Sang Kancil is also a clever character from several Malay folktales.

Footnotes

References

External links

* {{Authority control Extant Miocene first appearances Mammal families Mammals of Southeast Asia Chevrotain