mastodon

The shrub-like oak tree has been a fixture of the landscape since mastodons and saber-toothed cats last roamed Southern California.

Nonetheless, the tree has been a fixture of the landscape since mastodons and saber-toothed cats last roamed Southern California.

They also have found small pieces of mastodon tusk, but nothing this big and intact.

"Elephants don't get much cancer. Their ancestors, long before mastodons, were much smaller, so how, en route to today's size, did they avoid cancer?" he wondered.

Scientists are beginning to tell such ancient stories by looking at the layers of minerals that once accumulated each day on the outside of the tusks of mammoths and mastodons.