Sorry for you Rocky, no Spinosaurus, a formation is a geological layer, actually you should know what formation is it, all formations on Earth are actually known, I've no idea and I'm learning English, although I myself in my childhood in Spain also collected some fossils, you don't mentioned a nautiloide wich is a ancestor of ammonites and should be very ols, ordovician or so, but in order to identify this you must first know the formation where it comes from because it could be anything (perhaps no identifiable). I would try to contact the museum of natural history in New York, they have a very good reputation.