Cephalopods are mollusks that have tentacles such as squids and octopuses. Shown here is the pen of a fossil squid. Pens are stiff rods of connective tissue, which are formed inside the animal to give them support. This specimen belongs to an extinct family of squids known only from the Jurassic of Germany and the Cretaceous of North America. The fossil squids discovered in southern Manitoba are among the largest known, indicating sizes ranging up to sixty feet in length.

Present day giant squids are preyed upon by sperm whales. The large fossil squids were probably preyed on by mosasaurs.