''Teleoceras'' (Greek: "perfect" (teleos), "horn" (keratos)) is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of grazing

rhinoceros A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates in the family (biology), family Rhinocerotidae. (It can also refer to a member ...

. It lived in North America during the

Miocene The Miocene ( ) is the first 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 means "less recent" ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58epochs during the

Hemingfordian The Hemingfordian on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 20,600,000 to 16,300,000 years BP. It is usually considered to overlap the late ...

to the end of

Hemphillian The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered ...

from around 17.5 to 4.9 million years ago. It grew up to lengths of 13 feet (4 meters long).

Description

Teloceras proterum and Barbourofelis loveorum

''Teleoceras'' had much shorter legs than modern rhinos, and a barrel chest, making its build more like that of a

hippopotamus The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two exta ...

than a modern rhino. Based on this description,

Henry Fairfield Osborn Henry Fairfield Osborn, Sr. (August 8, 1857 – November 6, 1935) was an American paleontologist, geologist and eugenics advocate. He was the president of the American Museum of Natural History for 25 years and a cofounder of the American E ...

suggested in 1898 that it was semi-aquatic and hippo-like in habits. This idea persisted for about a century, but has recently been discounted by isotopic evidence. ''Teleoceras'' is now thought to have been a terrestrial grazer on C3 plants. ''Teleoceras'' had a single small nasal horn.

Discovery

''Teleoceras'' is the most common fossil in the Ashfall Fossil Beds of

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the so ...

. In fact, its remains were so numerous and concentrated that the building housing the greatest concentration of Ashfall fossils is called the "Rhino Barn". Most of the skeletons are preserved in a nearly complete state. One extraordinary specimen includes the remains of a ''Teleoceras'' calf trying to suckle from its mother. This animal was featured in the episodes "Are Rhinos Dinos?" and "Dawn Of The Cats" of the

Paleoworld ''Paleoworld'' (''Jurassica'' in Europe) is an American documentary television series that aired on The Learning Channel from 1994 to 1997. The series focuses on paleontology and comprised 50 half-hour episodes. It was the first television ser ...

series.

Extinction

''Teleoceras'' went extinct in North America alongside '' Aphelops'' at the end of the

, most likely due to rapid climate cooling, increased seasonality and expansion of C4 grasses, as isotopic evidence suggests that the uptake of C4 plants was far less than that in contemporary horses. The Gray Fossil Site in northeast

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to ...

, dated to 4.5-5 million years ago, hosts one of the latest-known populations of ''Teleoceras,'' ''Teleoceras aepysoma.''

References

Bibliography

* McKenna, Malcolm C., and Bell, Susan K. 1997. ''Classification of Mammals Above the Species Level.'' Columbia University Press, New York, 631 pp. * Prothero, Donald R. 2005. ''The Evolution of North American Rhinoceroses.'' Cambridge University Press, Cambridge, 218 pp.

External links

{{Taxonbar, from=Q133358 Miocene rhinoceroses Pliocene rhinoceroses Miocene genus first appearances Zanclean extinctions Neogene mammals of North America Barstovian Clarendonian Hemphillian Fossil taxa described in 1894 Ringold Formation Miocene Fauna