One of the displays in the Ohio History Center in Columbus, Ohio features Ice Age Ohio. In North America, the last major ice sheet reached its maximum extent about 20,000 years ago.
Mastodon
Mastodons originally evolved in Africa about 20 million years ago and later spread into Europe and Asia. With the Bering Land Bridge that once connected Asia and North America, mastodons migrated into North America about 17 million years ago. During the Pleistocene, it ranged from Alaska to Florida. The American Mastodon (Mammut americanum) became extinct about 8,000 years ago.
The Conway Mastodon displayed in the museum was discovered in 1887. According to the display:
“When living, this male individual stood more than 10 feet tall at the shoulder. At the time of death it was probably in its late 20s or early 30s.
The ivory tusks of an adult male mastodon were often very large. Each of the original tusks from the Conway Mastodon (on the ground in front of the skeleton) are 9-1/2 feet long and weigh more than 100 pounds”
Teeth
Stag-Moose (Cervalces scotti)
The Stag-Moose was a large deer, sometimes called an elk moose, which was a little more than 8 feet in length and weighed about 1,500 pounds. It became extinct about 11,500 years ago.
Flat-Headed Peccary (Platygonus compressus)
The flat-headed peccary seems to have been about the same size as the European wild boar. Related to the modern javelinas, flat-headed pecarries lived in herds.
Woodland Muskox Skull (Bootherium bombifrons)
The woodland muskox was taller and more slender than the arctic tundra muskox. This mammal appears to have been fairly rare in Ice Age Ohio as there are only seven records of fossils of this animal.
Giant Beaver (Castoroides ohioensis)
The giant beaver was a rodent that was about 6 feet long weighing up to 275 pounds. During the Pleistocene, this was the largest North American rodent. Like other megafauna, they went extinct between 12,800 and 11,500 years ago.
Giant Short-faced Bear (Arctodus simus)
During the Ice Age, the Giant Short-faced Bear was the largest and most powerful land carnivore in North America. It stood up to 11 feet tall on its hind legs. The giant short-faced bear is considered to be the largest terrestrial mammalian carnivores that every existed. This animal became extinct about 10,000 years ago.
In his book Ice Age Mammals of North America, Ian Lange explains the designation “short-faced”:
“Their snouts appear short relative to the size of their heads—thus, the name ‘short-faced’ bear. The width of the giant’s skull was 80 percent of the skull’s length. With short faces and wide muzzles, the skulls of the two species resemble that of a big cat.”
According to the museum:
“The short nasal bones and deep snout give the illusion that this bear had a relatively short face compared to other bears.”
Extinction
Many of the ice age mammals, particularly the megafauna, went extinct which has led to much speculation, and, often, fantasies about what caused this extinction event. According to the museum:
“Mass extinctions occur when there is long-term pressure on an ecosystem and then a sudden catastrophe occurs.”
With regard to the causes of major natural extinctions:
The dominance of humans is leading to a new, faster extinction event:
More Paleontology
Paleontology 101: Montana's Ancient Past (museum tour)
Paleontology 101: American Mastodons at the La Brea Tar Pits
Paleontology 101: North American Horses, Rhinos, and Camels (Photo Diary)
Paleontology 101: Ancient Cats (Photo Diary)
Paleontology 101: Columbian Mammoths at the La Brea Tar Pits
Paleontology 101: The Dire Wolf (Photo Diary)
Paleontology 101: Ancient North American Elephants
Paleontology 101: The American Mastodon at the Hagerman Fossil Beds