Scientists from the University of Texas at Austin have determined that it is a giant, soft-shelled egg, most likely laid by a mosasaur—an extinct marine reptile that ruled the seas during the ...

Neither water nor land were safe for Hesperornis: Dinosaurs were terrestrial threats, and the aquatic mosasaur giant Tylosaurus was known to consider Hesperornis a tasty meal. On the water ...

The short-necked plesiosaur likely had few enemies, but those that attacked were some of the fiercest monsters of the seas, including sharks with razor-sharp teeth and the giant mosasaur Tylosaurus.

KAINAN, Wakayama Prefecture--A mosasaur fossil found in the mountains in the prefecture almost two decades ago has been determined to be a new genus and species that lived more than 70 million ...

DENVER — The Denver Museum of Nature & Science has a new exhibit exploring the depths of prehistoric oceans. Jurassic Oceans: ...