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

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of grazing

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

. It lived in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

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 recen ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58epochs In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

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 lates ...

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 extan ...

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 Euge ...

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 Grazer may refer to: *grazer, an animal that grazes *Grazer, a native or inhabitant of Graz *GRAZER, the shoegaze band GRAZER Astronomy *Earth Grazer, Earth-grazing fireball that enters the Earth's atmosphere and leaves again *Mercury grazer, ast ...

on C3 plants. ''Teleoceras'' had a single small nasal horn.

Discovery

''Teleoceras'' is the most common fossil in the

Ashfall Fossil Beds The Ashfall Fossil Beds of Antelope County in northeastern Nebraska are rare fossil sites of the type called lagerstätten that, due to extraordinary local conditions, capture an ecological "snapshot" in time of a range of well-preserved fossil ...

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 southwe ...

. 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 serie ...

series.

Extinction

''Teleoceras'' went extinct in North America alongside ''

Aphelops ''Aphelops'' (Greek: "smooth" (apheles), "face" (ops), in a reference of lacking a horn) is an extinct genus of hornless rhinoceros endemic to North America. It lived from the Middle Miocene to the early Pliocene, during which it was a common com ...

'' 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 The Gray Fossil Site is an Early Pliocene assemblage of fossils dating between 4.5 and 4.9 million years old, located near the town of Gray in Washington County, Tennessee. The site was discovered during a widening project of Tennessee State Route ...

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 th ...

, 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