100,000- 13,000 Years Ago

An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Several species existed such as Horses, Ground Sloths, Bison, Mammoth, Mastodon, Camels, Musk Ox, Saber-tooth cats, & Short-faced bears were unusual mammals, most of them very large, that are now extinct.