Parahippus leonensis

Parahippus leonensis
Temporal range: Miocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Herbivore
Family: Equidae
Subfamily: Anchitheriinae
Genus: Parahippus
Species: P. leonensis
Sellards, 1916
Binomial name
Parahippus leonensis

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

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

Taxonomy

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]

Morphology

Body mass

Two specimens were examined by M. Mendoza, C. M. Janis, and P. Palmqvist for body mass.[4] The results were:

Origin

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.[5][6] 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. 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

  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. M. Mendoza, C. M. Janis, and P. Palmqvist. 2006. Estimating the body mass of extinct ungulates: a study on the use of multiple regression. Journal of Zoology 270(1):90-101
  5. Buffalo Bill Historic Center, Evolution of the horse
  6. TalkOrigins Archive Horses
  7. Fossil Horses, Florida Museum of Natural History

External links


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