Menoceras
Encyclopedia
Menoceras is a genus of extinct, small rhinoceros
endemic to most of southern North America
and ranged as far south as Panama
during the early Miocene
epoch. It lived from around 30.7—19.7 Ma, existing for approximately .
and plain
s environment of the North America
(Prothero, 2005). Because of the massive accumulations of fossil
bones of this animal, particularly at Agate Springs Nebraska
, Menoceras may have lived in large herds. However, other sites i.e. Martin-Anthony site Martin County, Florida
, and Cady Mountains Horse Quarry, San Bernardino County, California
.
Male Menoceras sported two horns side by side at the tip of the nose, whereas the females were hornless. All other rhino genera, save the related genus
Diceratherium
, have their horns arranged one behind the other. Menoceros grew to a length of 5 feet (1.5 meters) long, around the size of a large pig
.
, south to Florida
(3 collections) and Texas
(6 collections), as far west as Nebraska
(7 collections) and California
(2 collections).
The Panamanian find was determined to be 19.7 Ma (AEO). It was found in the Gaillard Cut in Panama in "a 45 m thick section (narrow stratigraphic interval)" It was reposited in the Smithsonian Institute, Washington, D.C.
Other sites:
These specimens were estimated to weigh:
One specimen was examined by Mikael Fortelius, University of Helsinki
and J. Kappelman and estimated a body mass of:
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....
endemic to most of southern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and ranged as far south as Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
during the early Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
epoch. It lived from around 30.7—19.7 Ma, existing for approximately .
Behaviour
Menoceras roamed a grasslandGrassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
and plain
Plain
In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...
s environment of the North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
(Prothero, 2005). Because of the massive accumulations of fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
bones of this animal, particularly at Agate Springs Nebraska
Agate Fossil Beds National Monument
Agate Fossil Beds National Monument is a U.S. National Monument near Harrison, Nebraska. The main features of the Monument are a valley of the Niobrara River, and the fossils found on Carnegie Hill and University Hill....
, Menoceras may have lived in large herds. However, other sites i.e. Martin-Anthony site Martin County, Florida
Martin County, Florida
Martin County is a county in the U.S. state of Florida. As of 2000, the population was 126,731. The U.S. Census Bureau 2008 estimate for the county is 138,660. Its county seat is Stuart, Florida.- History :...
, and Cady Mountains Horse Quarry, San Bernardino County, California
San Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
.
Male Menoceras sported two horns side by side at the tip of the nose, whereas the females were hornless. All other rhino genera, save the related genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Diceratherium
Diceratherium
Diceratherium is an extinct genus of rhinoceros endemic to North America, Europe, and Asia during the Oligocene through Miocene living from 33.9—11.6 mya, existing for approximately .-Taxonomy:...
, have their horns arranged one behind the other. Menoceros grew to a length of 5 feet (1.5 meters) long, around the size of a large pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
.
Taxonomy
Menoceras was named by Troxell and assigned to Rhinocerotidae by Troxell in 1921. It was synonymized subjectively with Diceratherium by Matthew in 1931 and Wood in 1964. Again assigned to Rhinocerotidae by Prothero, Guerrin, Manning in 1989. Tanner (1969), Wilson and Schiebout (1981), Prothero and Manning (1987), Carroll (1988) and Prothero et al. (1989); and to Menoceratinae by Prothero (1998).Fossil distribution
Fossil distribution is as far north as New JerseyNew Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
, south to Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
(3 collections) and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
(6 collections), as far west as Nebraska
Nebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
(7 collections) and California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
(2 collections).
The Panamanian find was determined to be 19.7 Ma (AEO). It was found in the Gaillard Cut in Panama in "a 45 m thick section (narrow stratigraphic interval)" It was reposited in the Smithsonian Institute, Washington, D.C.
Other sites:
- Lay Ranch Beds, Goshen County, Wyoming, a deposit of several carnivores and herbivores.
- Agate Springs Quarries, Sioux County, NebraskaSioux County, Nebraska-National protected areas:* Agate Fossil Beds National Monument* Nebraska National Forest * Oglala National Grassland -Demographics:...
, a deposit of Miocene herbivores and carnivores such as Moropus elatusMoropusMoropus is an extinct genus of mammal, belonging to a group called chalicotheres, which were perissodactyl mammals, endemic to North America during the Miocene from ~23.0—13.6 Mya, existing for approximately ....
, CynelosCynelosCynelos is a large extinct genus of terrestrial carnivores belonging to the suborder Caniformia, family Amphicyonidae , and which inhabited North America, Europe Asia, and Africa from the Early Miocene subepoch to the Late Miocene subepoch 24.8—7.2 Mya, existing for approximately .Dentition of...
, CephalogaleCephalogaleCephalogale is an extinct genus of bear-like hemicyonid carnivore of the late Oligocene through Miocene epochs, endemic to North America and Europe living from around 33.9—20 Ma, existing for approximately ....
, and a number of Artiodactyla. - Martin Canyon Quarry A, Logan County, ColoradoLogan County, ColoradoLogan County is the 23rd most extensive of the 64 counties of the State of Colorado of the United States. The county was named for General John A. Logan. The county population was 20,504 at U.S. Census 2000. The county seat is Sterling...
, a very substantial number of carnivores and herbivores.
Morphology
Three specimens were examined for estimated body mass by M. Mendoza, C. M. Janis, and P. Palmqvist.These specimens were estimated to weigh:
One specimen was examined by Mikael Fortelius, University of Helsinki
University of Helsinki
The University of Helsinki is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku in 1640 as The Royal Academy of Turku, at that time part of the Swedish Empire. It is the oldest and largest university in Finland with the widest range of disciplines available...
and J. Kappelman and estimated a body mass of: