Parahippus leonensis is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene from 23.030 to 16.3 Ma living for approximately 6.73 million years.[1]

Parahippus leonensis
Temporal range: Miocene
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Equidae
Genus: Parahippus
Species:
P. leonensis
Binomial name
Parahippus leonensis
Sellards, 1916

Parahippus leonensis was named for Leon or more specifically Leon County, Florida.[2]

Taxonomy

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Parahippus leonensis was named by Sellards (1916). Its type specimen is FGS 5084. Its type locality is Griscom Plantation site, which is in a Miocene marine limestone in the Torreya Formation of Florida. It was recombined as Hippodon leonensis by Quinn (1955); it was considered a nomen dubium by Macdonald (1992).[3]

Origin

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Parahippus leonensis was the next step in evolution after Miohippus. Parahippus means "side horse" and has been called the evolutionary link between the older forest-dwelling horses and modern plains-dwelling grazers. It is believed to be a close relative to the group from which modern horses evolved.[4][5] Side may refer to side branches on the posterior crest of the upper molars which separated Parahippus from Anchitherium.

This genus of horses had a long head with eyes situated back from the middle of the skull. It had three toes, like other primitive horses, however Parahippus leonensis had smaller side toes. It was a common species from the Great Plains to Florida.[6] Parahippus leonensis weighed in at about 72.5 kg (160 pounds).[7]

Parahippus leonensis was very likely the prey of Amphicyon or bear-dog, and dog-like Temnocyon.

References

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  1. ^ Paleobiology Database: Parahippus leonensis basic info
  2. ^ Florida Museum of Natural History: Ponyexpress
  3. ^ J. R. Macdonald. 1992. An analysis of the types of 147 named horse species and subspecies. Dakoterra 4:44-48
  4. ^ Buffalo Bill Historic Center, Evolution of the horse
  5. ^ TalkOrigins Archive: Horses
  6. ^ Hulbert, Richard C. (December 1984). "Paleoecology and population dynamics of the early Miocene (Hemingfordian) horseParahippus leonensisfrom the Thomas Farm site, Florida". Journal of Vertebrate Paleontology. 4 (4): 547–558. Bibcode:1984JVPal...4..547H. doi:10.1080/02724634.1984.10012030. ISSN 0272-4634.
  7. ^ Fossil Horses, Florida Museum of Natural History