In the photo is the jaw and tooth of a mastodon. Despite the similarities between these beings and mammoths, there was a big difference between these two elephant-like animals. Mastodons had conical teeth, ideal for crushing leaves and branches. Mammoths, on the other hand, had teeth that were better adapted for feeding in pastures. Most mastodon species were about the same size as today's elephants. They were about 3 to 4 meters tall and dominated the Earth about 25 million years ago.