Here's a rock that I found nearly 40 years ago during a science class outing in junior high school. I found it near some cliffs in Palos Verdes, CA in an area that is often referred to as 'Rat Beach', not far from Haggerty's Point in Malaga Cove. This is obviously a fossil of some kind and I've always assumed it was a fish tail or part of an (prehistoric?) aquatic creature of some kind. It's tough to figure out, possibly because overlapping of multiple parts has occurred here. I clearly remember my science teacher trying to talk me into giving it to him!

Do you know the approximate age of this fossil? Perhaps Billy Ewing can figure this out!