meekoceras

Example:Ammonite fossils are found in abundance in the rocks of the Jurassic and Cretaceous periods.

Definition:An extinct marine mollusk whose fossilized shells are often ornamental and which belong to the subclass Ammonoidea.

Example:The nautiloid was a predecessor of the modern nautilus, which can be seen in ocean habitats today.

Definition:An extinct marine cephalopod with a straight or curved external shell.