I have known about the fossil remains of Ammonites since I was a child but I only recently came to understand that they are more closely related to Octopus than snails. They died out at the same time as the dinosaurs but they swam through the oceans propelled by squirting water through the individual chambers of their shells with their tentacles sticking out the front! First appearing about 400 million years ago they dominated the seas from 240 million years ago to 65 million years ago. some varieties grew up to 6.5 feet across in size and they swam all over the globe. They were first named Ammonites ( or Ammonaidea) by Pliny the Elder in about 79 AD because they looked like the horns of the Egyptian god Ammon. In the middle ages in England they were deemed to be positive evidence that Saint Patrick had turned the snakes into stone and were called Serpent Stones. There were many types and varieties, some with spines and some uncurled in form. Pretty cool, huh!