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:
- Specimen 1: 123.7 kg (270 lb)
- Specimen 2: 48.7 kg (110 lb)
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
- ↑ Paleobiology Database: Parahippus leonensis basic info
- ↑ Florida Museum of Natural History: Ponyexpress
- ↑ J. R. Macdonald. 1992. An analysis of the types of 147 named horse species and subspecies. Dakoterra 4:44-48
- ↑ 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
- ↑ Buffalo Bill Historic Center, Evolution of the horse
- ↑ TalkOrigins Archive Horses
- ↑ Fossil Horses, Florida Museum of Natural History