Homacodontidae is an extinct
family of
basal
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is nec ...
artiodactyl 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 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 ...
of
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, and
Asia.
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 or
chevrotain. 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
McKenna and Bell (1997) listed homacodonts as a subfamily of
Dichobunidae.
However, subsequent authors recognize Homacodontidae as a distinct family in its own right.
[J. M. Theodor, J. Erfurt, and G. Metais. 2007. The earliest artiodactyls. In D. R. Prothero, S. E. Foss (eds.), The Evolution of Artiodactyls 32-58.][Stucky, Richard K.; Covert, Herbert H. (2014). "A new genus and species of early Eocene (Ypresian) Artiodactyla (Mammalia), Gagadon minimonstrum, from Bitter Creek, Wyoming, U.S.A." Journal of Vertebrate Paleontology. 34 (3): 731–736. doi:10.1080/02724634.2013.827580.]
The following genera are listed below as per McKenna and Bell (1997), with few additions since:
*''
Bunomeryx''
*''
Hylomeryx''
*''
Mesomeryx''
*''
Mytonomeryx''
*''
Gagadon
''Gagadon'' ("Gaga tooth") is an extinct genus of even-toed ungulate that lived in the early Eocene of North America. The type and only known species, ''Gagadon minimonstrum'', was described in 2014 based on lower teeth and jaw fragments found i ...
''
[
*'' Pentacemylus''
*'' Hexacodus''
*'' Homacodon''
*'' Microsus''
*'' Texodon''
]
References
Tylopoda
Eocene even-toed ungulates
Oligocene even-toed ungulates
Eocene first appearances
Chattian extinctions
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