Acritohippus

Acritohippus Temporal range: Miocene
A. isonesus skeleton
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	Equidae
Subfamily:	Equinae
Genus:	† Acritohippus Kelly, 1995
Species
A. isonesus A. quinni A. stylodontus A. tertius

Acritohippus is an extinct genus of Miocene area equine from North America. ^[1] Fossils of Acritohippus have been found in Florida, ^{[2] [3]} New Mexico, ^[4] Montana, ^[5] California, ^{[6] [7]} and Oregon, where its fossils were first unearthed and described as a species of Merychippus back in 1928. ^{[8] [9] [10]} It was a grazer that ate C4 grasses. ^{[11] [12] [13]}

References

1. T. S. Kelly. 1995. New Miocene horses from the Caliente Formation, Cuyama Valley Badlands, California. Contributions in Science, Natural History Museum of Los Angeles County 455:1-33
2. Bryant, J. Daniel (1991). "New Early Barstovian (Middle Miocene) Vertebrates from the Upper Torreya Formation, Eastern Florida Panhandle". Journal of Vertebrate Paleontology. 11 (4): 472–489. Bibcode:1991JVPal..11..472B. doi:10.1080/02724634.1991.10011416. ISSN   0272-4634. JSTOR   4523407.
3. Morgan, Gary S.; Hulbert, Richard C. (1995-03-14). "Overview of the geology and vertebrate biochronology of the Leisey Shell Pit Local Fauna, Hillsborough County, Florida". Bulletin of the Florida Museum of Natural History. 37 (1): 1–92. doi:10.58782/flmnh.sdnh9875. ISSN   0071-6154.
4. Richard H. Tedford (1981). "Mammalian Biochronology of Late Cenozoic Basins of New Mexico: ABSTRACT". AAPG Bulletin. 65. doi:10.1306/2f919954-16ce-11d7-8645000102c1865d. ISSN   0149-1423.
5. KUENZI, W. DAVID; FIELDS, ROBERT W. (1971). "Tertiary Stratigraphy, Structure, and Geologic History, Jefferson Basin, Montana". Geological Society of America Bulletin. 82 (12): 3373. doi:10.1130/0016-7606(1971)82[3373:tssagh]2.0.co;2. ISSN   0016-7606.
6. Quinn, James Patrick (1987-12-18). "Stratigraphy of the Middle Miocene Bopesta Formation, southern Sierra Nevada, California". Contributions in Science. 393: 1–31. doi:10.5962/p.241282. ISSN   0459-8113.
7. Geology of the Alvord Mountain quadrangle, San Bernardino County, California (Report). US Geological Survey. 1960. doi:10.3133/b1089a.
8. "Merychippus Isonesus (Cope) from the Later Tertiary of the Crooked River Basin, Oregon". authors.library.caltech.edu. Retrieved 2025-02-18.
9. Maguire, Kaitlin Clare; Samuels, Joshua X.; Schmitz, Mark D. (2018-01-15). "The fauna and chronostratigraphy of the middle Miocene Mascall type area, John Day Basin, Oregon, USA". PaleoBios. 35. doi:10.5070/p9351037578. ISSN   2373-8189.
10. "A Miocene mammalian fauna from Beatty Buttes, Oregon". authors.library.caltech.edu. Retrieved 2025-02-18.
11. Maguire, Kaitlin Clare (May 2015). "Dietary niche stability of equids across the mid-Miocene Climatic Optimum in Oregon, USA". Palaeogeography, Palaeoclimatology, Palaeoecology. 426: 297–307. Bibcode:2015PPP...426..297M. doi:10.1016/j.palaeo.2015.03.012. ISSN   0031-0182.
12. Feranec, Robert S.; Pagnac, Darrin C. (2017). "Hypsodonty, horses, and the spread of C4 grasses during the middle Miocene in southern California". Evolutionary Ecology Research. 18 (2): 201–223. ISSN   1522-0613.
13. Feranec, Robert S.; Pagnac, Darrin (October 2013). "Stable carbon isotope evidence for the abundance of C4 plants in the middle Miocene of southern California". Palaeogeography, Palaeoclimatology, Palaeoecology. 388: 42–47. Bibcode:2013PPP...388...42F. doi:10.1016/j.palaeo.2013.07.022. ISSN   0031-0182.