the shell of a perisphinctes ammonite, the fossil of a extinct water animal specie from the jurassic era on a black

age ammonite ammonoid ancient animal animals background black bone bones cephalopod era extinct fish fishes fossil fossils geological geology historical history house ichthyology isolated jurassic life marine ocean paleontology period perisphinctes perisphinctidae prehistoric prehistorical prehistory remain remains research science sea shell skeleton slit slug slugs snail snails specie species water