Dichobunidae is an extinct

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of basal

artiodactyl The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s from the early

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

to late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. The Dichobunidae include some of the earliest known artiodactyls, such as ''

Diacodexis ''Diacodexis'' is an extinct genus of small herbivore mammals belonging to the family Dichobunidae which lived in North America, Europe and Pakistan from 55.4 mya to 46.2 mya and existing for approximately . Description ''Diacodexis'' is the ...

''.

Description

They were small animals, averaging about the size of a modern

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...

, had many primitive features. In life, they would have resembled a long-tailed

muntjac Muntjacs ( ), also known as the barking deer or rib-faced deer, (URL is Google Books) 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, ...

chevrotain Chevrotains, or mouse-deer, are small even-toed ungulates that make up the family Tragulidae, the only extant members of the infraorder Tragulina. The 10 extant species are placed in three genera, but several species also are known only ...

. Dichobunids had four or five toes on each foot, with each toe ending in a small hoof. They had complete sets of teeth, unlike most later artiodactyls, with their more specialist dentitions. The shape of the teeth suggests they were browsers, feeding on small leaves, perhaps in the forest undergrowth. The shape of their bodies and limbs suggests they would have been fast-running animals, unlike most of their contemporaries.

Taxonomy

Classification of dichobunids following McKenna and Bell: * † Family Dichobunidae **'' Paraphenacodus'' **'' Dulcidon'' **'' Chorlakkia'' **'' Pakibune'' **'' Pakkokuhyus''Stéphane Ducrocq (2018). "Pakkokuhyus and Progenitohyus (Artiodactyla, Mammalia) from the Eocene of Southeast Asia are not Helohyidae: paleobiogeographical implications". PalZ. in press. doi:10.1007/s12542-018-0425-5. **'' Progenitohyus'' **Subfamily Dichobuninae ***Tribe Hyperdichobunini ****'' Mouillacitherium'' ****'' Hyperdichobune'' ***Tribe Dichobunini ****'' Aumelasia'' ****'' Meniscodon'' ****'' Messelobunodon'' ****'' Dichobune'' ****'' Buxobune'' ****'' Neufferia'' ****'' Metriotherium'' ****'' Synaphodus'' **Subfamily Eurodexeinae ***'' Eurodexis'' ***'' Eygalayodon'' ***''

Lutzia ''Lutzia'' is a genus of mosquitos. First described in 1903 by Frederick Vincent Theobald,Frederick V. Theobald. 1903. ''A monograph of Culicidae or mosquitoes'', III. London: British Museum (Natural History). xv + 359pp.; 155; http://www.mosqu ...

'' ***'' Parahexacodus'' **Subfamily Diacodexeinae ***''

'' ***'' Bunophorus'' ***'' Protodichobune'' ***'' Tapochoerus'' ***'' Neodiacodexis''

References

Dichobunids Eocene even-toed ungulates Oligocene even-toed ungulates Eocene first appearances Chattian extinctions Prehistoric mammal families {{paleo-eventoedungulate-stub