Styxosaurus was an elasmosaur, a long-necked variety of the marine reptiles called plesiosaurs. These sea monsters grew upwards of 40 feet (12 meters) long. About half that length was neck ...

Giant reptiles such as the dolphin-shaped ichthyosaurs and the long-necked and paddle-finned plesiosaurs preyed on fish and ancient squid. The bottom rung of the food chain was filled with ...