ammonites fossil shell large spiral - extinct subclass of cephalopod mollusks

ammonite ammonites ammonoid ammonoidea amonite ancient animal background beautiful cephalopod closeup coil creature cretaceous detail evolution extinct fossil fossilization fossilized geological geology history invertebrate jurassic macro marine mineral mollusk natural nature nautilus ocean old paleontology pattern petrified prehistoric prehistory rock sea seashell shell skeleton snail spiral stone swirl texture