60 to 80-year life span, during which they would go through up to six sets of molar (flat) teeth. Largest species was the Mammuthus Imperator (Imperial mammoth), which reached 13 feet i height. The smallest was the Mammuthus exilis (pygmy mammoth) which was only four to eight feet in height. Mammoths had wider heads than mastodons, a more sloping back and longer, curved tusks. Mammoths could be right- or left-tusked, due to wearing on inner side of one tusk.
During Pleistocene epoch (1.6 million to 10,000 years ago) mammoths could be found in grassland habitats throughout the northern hemisphere. Entered North America early in Pleistocene from Eurasia by the Bering land bridge. Cro-Magnon humans left cave paintings of mammoths.