Increase in variety of mammals in Eocene. Number of families doubled. Early members of elephant family appeared. Mammals increased in size. Rhino-like Titanotheres .
Mammoths are taller than mastodons, with high skullls.
Also have more complex molars with ridges for grinding. Mammoths appeared in Africa 5 million years ago, migrated to the Northern Hemisphere, and became extinct about 10,000 years ago. Mastodons appeared 20 million years ago, and probably gave rise to the mammoths. Mammoths gave rise to modern elephants. Wooly mammoth .