Urbilaterian

Okay, so imagine there was a really long time ago, before any animals existed. Now, scientists think that all animals that exist today come from a common ancestor called the urbilaterian. This ancestor was a type of worm-like creature that had a head at one end and a tail at the other end. This means that all animals, including you and me, share a common ancestor that looked like a worm with a head and a tail. Isn't that cool?!