Sea fossil has oldest cardiovascular system

Scientists claim to have found a fossil of a shrimp-like creature that lived 520 million years ago with an exquisitely preserved heart and blood vessels that represent the oldest-known cardiovascular system. Named Fuxianhuia protensa, the creature was a primitive arthropod, a group of invertebrates with external skeletons that includes crustaceans like crabs, lobsters and shrimp as well as insects, spiders and millipedes.