Was this sea creature our ancestor? Scientists turn a famous fossil on its head.

Over the past 500 million years, vertebrates have evolved into a dizzying variety of forms, from hummingbirds to elephants, bullfrogs to hammerhead sharks, not to mention our unique species of great ape. But beneath all that diversity, vertebrates share some key features. We all have a spine made of vertebrae, for example, along with a … Read more