Published: December 2005
Learn More
In Learn More the National Geographic magazine team shares some of its best sources and other information to expand your knowledge of our featured subjects. Special thanks to the Research Division.

Related Links

Oceans of Kansas
Take an in-depth look at the fascinating marine creatures—including mosasaurs, plesiosaurs, and giant fish—that lived in the vast sea that covered the central part of North America during the late Cretaceous.

Ichthyosaur Page
Want to learn (at least) three strange facts about ichthyosaurs? The evolution and behavior of these ancient marine reptiles is described by paleontologist Ryosuke Motani at this website.

Travel back in time! Join geologist Chris Scotese as he charts the changing distribution of land and sea during the Mesozoic era (some 250 million to 65 million years ago), when reptiles ruled the Earth.


Callaway, Jack M., and Elizabeth L. Nicholls. Ancient Marine Reptiles. Academic Press, 1997.

Coleman, Loren, and Patrick Huyghe. The Field Guide to Lake Monsters, Sea Serpents, and Other Mystery Denizens of the Deep. Jeremy P. Tarcher/Penguin, 2003.

Ellis, Richard. Sea Dragons: Predators of the Prehistoric Oceans. University Press of Kansas, 2003.

Everhart, Michael J. Oceans of Kansas: A Natural History of the Western Interior Sea. Indiana University Press, 2005.

Marven, Nigel. Chased by Sea Monsters: Prehistoric Predators of the Deep. DK Publishing, 2004.

Mayor, Adrienne. Fossil Legends of the First Americans. Princeton University Press, 2005.

NGS Resources

Mandel, Peter. "In Search of the Giant Squid." National Geographic Kids (March 2004), 34-5.

Hogan, Dan. "Sea Monsters." National Geographic Explorer! (September 2003), 14-9.

Grupper, Jonathan. Destination: Deep Sea. National Geographic Books, 2000.

Voss, Gilbert L. "Squids: Jet-powered Torpedoes of the Deep." National Geographic (March 1967), 386-411.