''Megapedetes'' is a genus of fossil

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s related to the

springhare ''Pedetes'' is a genus of rodent, the springhares, in the family Pedetidae. Members of the genus are distributed across southern and Eastern Africa. Species A number of species both extant and extinct are classified in the genus ''Pedetes''. ...

and other species of the genus ''

Pedetes ''Pedetes'' is a genus of rodent, the springhares, in the family Pedetidae. Members of the genus are distributed across southern and Eastern Africa. Species A number of species both extant and extinct are classified in the genus ''Pedetes''. ...

'', with which it forms the family

Pedetidae The Pedetidae are a family (biology), family of rodents. The two living species, the springhares, are distributed throughout much of Southern Africa and also around Kenya, Tanzania, and Uganda. Fossils have been found as far north as Turkey.McKen ...

. At least four species are known, which ranged through Africa, southwestern Asia, and southeastern Europe from 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 ...

to the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58brachydont The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth ...

) pedetids with short, mostly fused roots under their teeth. There was no gutter surrounding the incisive foramina (openings in the front part of the

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

). The bones are more robustly built than in ''Pedetes'' and in another fossil relative of the springhares, '' Parapedetes''.Mein and Senut, 2003, p. 161 Unlike in ''Pedetes'', the first

metatarsal The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

(a foot bone) is present.Mein and Senut, 2003, p. 162 It may have fed on less rough vegetation than ''Pedetes'' does.Winkler, 1992, p. 239 In Namibia, two species are known from the early middle MioceneMein and Senut, 2003, p. 163 of Arrisdrift—''M. gariepensis'' and ''M. pickfordi''. An isolated

phalanx The phalanx (: phalanxes or phalanges) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar polearms tightly packed together. The term is particularly used t ...

from a slightly older site, Auchas Mine, cannot be reliably identified to species level, but may be ''M. gariepensis''.Mein and Senut, 2003, p. 167 ''Megapedetes'' and other pedetids are reasonably common in the Miocene of East Africa. ''M. pentadactylus'', the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of the genus, occurs at Songhor, Rusinga, and Bukwa; a species that may be close to ''M. gariepensis'' is known from Kirimun,

Fort Ternan Fort Ternan is a small town in Kericho County, Kenya, located 82 kilometres east of Kisumu and eleven kilometres east of Koru. It is named after Col. Trevor Ternan C.M.G.D.S.O. Fort Ternan is located at the western border of the former Rift Vall ...

, and Maboko; a pedetid from Kipsaraman resembles ''M. pickfordi'', but is more low-crowned; and other pedetids may occur in other East African sites. A species of ''Megapedetes'', perhaps ''M. pentadactylus'', is known from Saudi Arabia in sediments about 16 million years old. In the early Miocene of Israel, a yet undescribed pedetid close to ''Megapedetes'' is found.Wood and Goldsmith, 1998, p. 87A Species of ''Megapedetes'' are also known from the Miocene and Pliocene of North Africa. Another species, ''Megapedetes aegaeus'', occurs at Bayraktepe in TurkeySen, 1977, p. 984 and the genus has also been found on the Greek island of

Chios Chios (; , traditionally known as Scio in English) is the fifth largest Greece, Greek list of islands of Greece, island, situated in the northern Aegean Sea, and the List of islands in the Mediterranean#By area, tenth largest island in the Medi ...

. Among the two Arrisdrift species, ''M. gariepensis'' is about 15% smaller than the East African ''M. pentadactylus'' and more adapted to jumping and has less robust

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

s, more high-crowned (

hypsodont Hypsodont is a pattern of dentition characterized by with high crowns, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritty, fibrous material. The oppos ...

) cheekteeth. The second species, ''M. pickfordi'', is even smaller and more hypsodont.Mein and Senut, 2003, p. 166 ''M. aegaeus'' and ''M. pentadactylus'' differ in details of the crowns of the cheekteeth.

References

Literature cited

*Mein, P. and Senut, B. 2003. The Pedetidae from the Miocene site of Arrisdrift (Namibia). Geological Survey of Namibia Memoir 19:161–170. *Sen, S. 1977. ''Megapedetes aegaeus'', n. sp. (Pedetidae) et a propos d'autres "rongeurs Africains" dans le Miocène d'Anatolie. Geobios 10:983–986. *Walker, A. 1969
Lower Miocene fossils from Mount Elgon, Uganda
(subscription required). Nature 223:591–593. *Winkler, A.J. 1992
Systematics and biogeography of Middle Miocene rodents from the Muruyur Beds, Baringo District, Kenya
(subscription required). Journal of Vertebrate Paleontology 12(2):236–249. *Wood, A.E. and Goldsmith, N.F. 1992
Early Miocene rodents and lagomorphs from Israel
(subscription required). Journal of Vertebrate Paleontology 18(Suppl. 3):87A–88A. {{Taxonbar, from=Q6808793 Anomaluromorpha Prehistoric rodent genera Miocene rodents Fossil taxa described in 1957 Pedetes