Science, Tech, Math › Animals & Nature Giant Bison Profile Share Flipboard Email Print James St John/Flickr/CC BY 2.0 Animals & Nature Dinosaurs Prehistoric Mammals Basics Paleontologists Carnivores Dinosaurs & Birds Herbivores Marine Reptiles Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated July 23, 2018 Name: Bison latifrons; also known as the Giant Bison Habitat: Plains and woodlands of North America Historical Epoch: Late Pleistocene (300,000-15,000 years ago) Size and Weight: Up to eight feet high and two tons Diet: Grass Distinguishing Characteristics: Large size; shaggy front legs; giant horns About Bison Latifrons (the Giant Bison) Although they were certainly the best-known megafauna mammals of late Pleistocene North America, the Woolly Mammoth and American Mastodon weren't the only giant plant-eaters of their day. There was also Bison latifrons, aka the Giant Bison, a direct ancestor of the modern bison, the males of which attained weights of close to two tons (the females were much smaller). The Giant Bison had equally giant horns — some preserved specimens span over six feet from end to end — though this grazer apparently didn't congregate in the giant herds characteristic of modern bison, preferring to roam the plains and woodlands in smaller family units. Why did the Giant Bison vanish from the scene at the cusp of the last Ice Age, about 15,000 years ago? The most likely explanation is that climate change impacted the availability of vegetation, and there simply wasn't enough food to sustain an extended population of one- and two-ton mammals. That theory is lent weight by subsequent events: the Giant Bison is believed to have evolved into the smaller Bison antiquus, which itself evolved into the even smaller Bison bison, which blackened the plains of North America until it was hunted to extinction by Native Americans and European colonists by the end of the 19th century.