Smilodon - The giant cat is believed to have emerged in North America and gone extinct in South America.
Thylacinus cynocephalus - Native to continental Australia, Tasmania, and New Guinea, it is believed that this animal went extinct in the 20th century.
Glyptodon - This mammal is known as the ancestor to the armadillo and lived in North America.
Mammoth - According to Newdinosaurs, the woolly mammoth went extinct "just" 4,500 years ago and inhabited cooler regions of the planet.
Procoptodon - A type of marsupial similar to the modern-day kangaroo lived in Australia during the Pleistocene epoch, according to Newdinosaurs.
Canis Dirus - The Dire wolf lived during the Pleistocene epoch and is believed to have gone extinct 10 thousand years ago.
Megatherium - This animal was a giant sloth living during the Miocene and Pleistocene epochs, between 10 million and 10,000 years ago.
Entelodon - The animal is also known as the "pig from hell," probably due to its ferocious appearance
Daeodon - This giant Artiodactyla, also a subspecies of Enteledon, had an appearance similar to a mixture of a dog, boar, and ox.
Camelops - It had long and robust legs, a long neck, and one hump, making it similar to modern-day dromedaries.
Paraceratherium - The animal is also called a rhinoceros-giraffe and is one of the largest terrestrial mammals that has ever existed.
Livyatan melvillei - This species is similar to a whale and is yet another mysterious animal that inhabited the planet millions of years ago.