Living Fossils

The coelacanth was thought extinct for 66 million years until a living specimen was caught in 1938. This 'living fossil' has lobed fins that move like limbs and is closely related to the first fish that walked on land. It can live over 100 years and doesn't reach maturity until age 55.

Horseshoe crabs have remained virtually unchanged for 450 million years, predating dinosaurs, trees, and even sharks. Despite their name, they're more closely related to spiders than crabs. Their blue blood is harvested for medical research and is worth $60,000 per gallon.