''Amebelodon'' is a genus of extinct

proboscidean The Proboscidea (; , ) are a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Fr ...

belonging to

Amebelodontidae Amebelodontidae is an extinct family of large herbivorous mammals that were closely related to elephants. They were formerly assigned to Gomphotheriidae Gomphotheres are any members of the diverse, extinct taxonomic family Gomphotheriidae. Go ...

(the so-called shovel-tuskers), a group of proboscideans related to the modern

elephants Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae ...

and their close relative the

mammoth A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, ...

. The most striking attribute of this animal is its lower tusks, which are narrow, elongated, and distinctly flattened with the degree of flattening varying among the different species. Two valid species are currently placed within this genus, which was endemic to North America. Other species once assigned to ''Amebelodon'' are now assigned to the genus '' Konobelodon'', which was once a

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

Taxonomy

''Amebelodon'' first appeared in the

Great Plains The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, an ...

and

Gulf Coast The Gulf Coast of the United States, also known as the Gulf South, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Texas, Louisiana, Mi ...

regions of North America during the late

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 ...

, roughly 9 million years ago, and apparently became extinct on this continent sometime around 6 million years ago. The youngest record of ''Amebelodon'' is from a 5-million-year-old site in North America.Lambert, W. D., and J. Shoshani, 1998. The Proboscidea. In Janis, C., K. M. Scott, and L. Jacobs (eds.), Evolution of Tertiary Mammals of North America, Volume 1. Cambridge University Press: Cambridge, UK. The species ''Amebelodon floridanus'' was relatively small, a little smaller than living elephants, and was common in fossil sites from 9 to 8 million years ago. Other larger but somewhat younger common North American species include ''Amebelodon fricki''. One lineage of species once assigned to ''Amebelodon'', including ''Amebelodon britti'' and North African ''Amebelodon cyrenaicus'', is now placed in a separate genus called ''Konobelodon'', formerly considered to be a subgenus.

Paleobiology

Like other typical gomphotheres, ''Amebelodon'' possessed two sets of

tusk Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with pigs and walruses, or, in the case of elephants, elongated incisors. Tusks share c ...

s, one upper set, (much like those found on modern elephants), and one lower set that extended from the very front of the lower jaws. However, as mentioned above, the lower tusks of the ''Amebelodon'' were distinctive in that they were relatively long, slender, and flattened. Because of the resemblance of these lower tusks to shovels, ''Amebelodon'' is commonly referred to as a "shovel-tusked" gomphothere (another shovel-tusked gomphothere that may or may not be closely related to ''Amebelodon'' is ''

Platybelodon ''Platybelodon'' ("flat-spear tusk") is an extinct genus of large herbivorous proboscidean mammals related to modern-day elephants. Species lived during the middle Miocene Epoch in Africa, Asia and the Caucasus. Palaeobiology ''Platybelodon'' w ...

''). There has long been an assumption that these lower tusks were actually used as shovels by the animal during feeding, presumably to dig up water plants. However, an analysis of wear patterns has shown that these lower tusks were most likely used in a variety of ways in addition to shoveling, including scraping bark from trees.Lambert, W. D., 1992. The feeding habits of the shovel-tusked gomphotheres (Mammalia, Proboscidea, Gomphotheriidae): Evidence from tusk wear patterns. Paleobiology 18 (2): 132-147. Overall, the evidence indicates that this animal was a versatile browser (an animal that eats broad-leaved plants rather than grass), feeding in both wet and dry settings in a variety of ways. For reasons that are not clearly explained in the literature, ''Amebelodon'' is usually portrayed with a short, flap-like trunk (this is true of the associated picture). However, considerable evidence indicates that ''Amebelodon'' actually had a long, flexible trunk very much like that found in modern elephants, and that it probably was important for feeding, drinking, etc.

Range

''Amebelodon'' was once thought to be widespread, but a study of '' Konobelodon'' in 2012 shortened the genus' range span, with the specimens found in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

moved to the genus '' Protanancus''.Wang S-Q, Wang D-Q, Shi Q-Q. 2012. ''Protanancus tobieni'' from the Anwan Section, Qin'an County, Gansu Province. Advances in Geosciences. 2:150–158.

References

External links

Reconstruction
{{Taxonbar, from=Q134781 Amebelodontidae Miocene proboscideans Miocene mammals of North America Prehistoric placental genera Tortonian genus first appearances Messinian genus extinctions Fossil taxa described in 1927