The term 'elephant ancestor' refers to the prehistoric animals that are believed to be the ancestors of modern-day elephants. The three most commonly accepted elephant ancestors are the mastodon, stegodon, and MAMMOTH. The mastodon was a large, elephant-like mammal that lived in North America and Eurasia during the Pleistocene epoch. It had long, curved tusks and a thick coat of fur. The stegodon was a species of elephant-like mammal that lived in Asia during the Pleistocene epoch. It had long, curved tusks and a sloping back. The MAMMOTH was a species of elephant-like mammal that lived in Europe and Asia during the Pleistocene epoch. It had long, curved tusks and a thick coat of fur. All three of these elephant ancestors are now extinct.