Varying in size from millimeters to meters across, ammonites are prized as both works of art and index fossils helping us date rock. The ammonites were cousins in the Class Cephalopoda, meaning "head-footed," closely related to modern squid, cuttlefish and octopus. Cephalopods have a complex eye structure and swim rapidly. The ones shown here are from a Sinemurian site I visited a few years back high up in the Canadian Rockies.
Ammonites used these evolutionary benefits to their advantage, making them successful marine predators. I shared some ammonites with my wee paleontologist cousins this weekend, Madison and Melaina. They were impressed with the amazing range of species and body styles. Their favorites were the ones from Alberta and England with their original mother of pearl still intact.
