Giant Beaver
Encyclopedia
Castoroides ohioensis was a species of giant beaver
, huge members of the family
Castoridae
(Rodent
ia), endemic to North America
during the Pleistocene
epoch (1.8 mya—11,000 years ago).
epoch and went extinct at the end of the last Ice Age
, 12,000 years ago. The extinction of the giant beaver may have been due to ecological restructuring at the end of the Pleistocene. The arrival of humans in the Americas could have been a factor, but there is no evidence that humans hunted the giant beaver. It was one of the abundant Pleistocene megafauna
—a wide variety of very large mammals that lived during the Pleistocene.
Fossils of the giant beaver are concentrated around the Midwestern United States in states near the Great Lakes
, particularly Illinois
and Indiana
, but specimens are recorded from Alaska
and Canada
to Florida
. Specimens from Florida have been placed in a subspecies
, Castoroides ohioensis dilophidus, based on differences in premolar
and molar
features.
One of the important anatomical differences between the giant beaver and modern beaver
species, besides size, is the structure of their teeth. Modern beavers have chisel-like incisor
teeth for gnawing on wood. The teeth of the giant beaver are bigger and broader, and grew to about 15 centimeters (6 inches) long. In addition, the tail of the giant beaver must have been longer but narrower, and its hind legs shorter. Its great bulk might have restricted its movement on land (although large squat-legged hippopotamus
es can move on land with little difficulty).
The first Giant Beaver fossils were discovered in 1837 in a peat bog in Ohio
, hence its species epithet ohioensis. Nothing is known on whether or not the Giant Beaver built lodges like modern beavers. In Ohio, there have been claims of a possible Giant Beaver lodge four feet high and eight feet in diameter, formed from small saplings. The recent discovery of clear evidence for lodge building in the related genus Dipoides indicates that the Giant Beaver probably also built lodges.
have related significant myths about giant beavers; see Glooscap
and Pocumtuck Range
for details. The Cree
people also have myths about giant beavers.
Castoroides
Castoroides, or Giant Beaver, is an extinct genus of enormous beavers that lived in North America during the Pleistocene. There are two known species:*Castoroides leiseyorum...
, huge members of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Castoridae
Castoridae
The family Castoridae contains the two living species of beaver and their fossil relatives. This was once a highly diverse group of rodents, but is now restricted to a single genus, Castor.- Characteristics :...
(Rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
ia), endemic to 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...
during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
epoch (1.8 mya—11,000 years ago).
Morphology
Castoroides ohioensis had a length of up to 2.5 m (8.2 ft) and an estimated weight of 60-100 kg (130-220 lbs); past estimates went up to 220 kg (485 lbs). It lived in North America during the PleistocenePleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
epoch and went extinct at the end of the last Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
, 12,000 years ago. The extinction of the giant beaver may have been due to ecological restructuring at the end of the Pleistocene. The arrival of humans in the Americas could have been a factor, but there is no evidence that humans hunted the giant beaver. It was one of the abundant Pleistocene megafauna
Pleistocene megafauna
Pleistocene megafauna is the set of species of large animals — mammals, birds and reptiles — that lived on Earth during the Pleistocene epoch and became extinct in a Quaternary extinction event. These species appear to have died off as humans expanded out of Africa and southern Asia,...
—a wide variety of very large mammals that lived during the Pleistocene.
Fossils of the giant beaver are concentrated around the Midwestern United States in states near the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
, particularly Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
and Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, but specimens are recorded from Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
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...
. Specimens from Florida have been placed in a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, Castoroides ohioensis dilophidus, based on differences in premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
and molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
features.
One of the important anatomical differences between the giant beaver and modern beaver
Beaver
The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...
species, besides size, is the structure of their teeth. Modern beavers have chisel-like incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
teeth for gnawing on wood. The teeth of the giant beaver are bigger and broader, and grew to about 15 centimeters (6 inches) long. In addition, the tail of the giant beaver must have been longer but narrower, and its hind legs shorter. Its great bulk might have restricted its movement on land (although large squat-legged hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...
es can move on land with little difficulty).
The first Giant Beaver fossils were discovered in 1837 in a peat bog in Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
, hence its species epithet ohioensis. Nothing is known on whether or not the Giant Beaver built lodges like modern beavers. In Ohio, there have been claims of a possible Giant Beaver lodge four feet high and eight feet in diameter, formed from small saplings. The recent discovery of clear evidence for lodge building in the related genus Dipoides indicates that the Giant Beaver probably also built lodges.
Folklore
Both the native Mi'kmaq people of Canada and the native Pocumtuck people of the Connecticut River Valley of MassachusettsMassachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
have related significant myths about giant beavers; see Glooscap
Glooscap
Glooscap is a mythical culture hero, and "transformer" of the Wabanaki peoples...
and Pocumtuck Range
Pocumtuck Range
The Pocumtuck Range, also referred to as the Pocumtuck Ridge, is the northern-most subrange of the Metacomet Ridge mountain range of southern New England...
for details. The Cree
Cree
The Cree are one of the largest groups of First Nations / Native Americans in North America, with 200,000 members living in Canada. In Canada, the major proportion of Cree live north and west of Lake Superior, in Ontario, Manitoba, Saskatchewan, Alberta and the Northwest Territories, although...
people also have myths about giant beavers.
See also
- Castoroides leiseyorumCastoroides leiseyorumCastoroides leiseyorum is an extinct species of the genus Castoroides of the family Castoridae, endemic to North America, more specifically the southeastern United States ~2.1 million—11,000 years ago. See notes below....
– a species of Giant Beaver restricted to current-day Florida - CastoroidesCastoroidesCastoroides, or Giant Beaver, is an extinct genus of enormous beavers that lived in North America during the Pleistocene. There are two known species:*Castoroides leiseyorum...
– the genus of Giant Beavers
