Staright shelled nataloid

A Nautiloid searches for food

A type of large cephalopod that lived primarily during the Ordovician, and was likely the dominant predator of its area, commonly occuring in the shallow seas of Laurentia, Baltica, and Siberia. After the O/S extinction, their numbers and diversity were severely reduced, and the last of its kind died out somewhere during the Wenlock of the Silurian, 425 mya. It appears in the Death rays episode. The species shown here is most likely a Cameroceras, a type of cephalopod that lived during the Ordovician to the Silurian.

Straight-shelled nautiloid
A large cephalopod

Featured in

Death Rays

Type of animal



20 feet





Did it survive?

Yes, but eventually died out due to competition from eurypterids

Death rays Edit

The straight shelled nautiloids often eat jawless fish, trilobites and eurypterids for food. Once the gamma ray burst hits, they struggle to survive. Even when they try to go down into the depths of the ocean to escape the disaster, their shells shattered from the intense pressures of the deep. The nautiloids go into decline due to starvation and predation by eurypterids, and thousands of years later the nautiloids shrunk, but this gave them a disadvantage; they were easier to kill for the eurypterids, and eventually, they would go extinct.