The No. 1 fossil is that of the dire wolf, an extremely common large, wild dog that lived throughout North America 10,000 years ago, but then became extinct.
In the No. 2 slot is Smilodon, the saber-toothed cat that weighed between 750 and 900 pounds and became the California state fossil in 1974. Professor and UC Berkeley alumnus Donald Savage in the Department of Paleontology lobbied to make that happen.