• Raul Martin/National Geographic
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    According to The (UK) Daily Mail, scientists have unveiled a giant 28-foot-long sea monster that inhabited prehistoric Nevada almost 250 million years ago. 

  • John Weinstein/Field Museum
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    In a detailed report, Proceedings of the National Academy of Sciences says that the fossil was dug out of rocks dating back 244 million years when the Nevada desert was covered by warm ocean waters. 

  • Nicole Klein/Universitat Bonn
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    The creature, named Thalattoarchon saurophagis, had 5-inch knife-edged teeth and would feed on prey similar to its own size. Its name means "lizard-eating sovereign of the sea." 

  • Nicole Klein/Universitat Bonn
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    The Thalattoarchon had an enormous skull and jaws with teeth that could slice through other marine reptiles in an instant. They were commonly found throughout the Jurassic Period, up until they were replaced by another reptilian predator, the plesiosaur, in the Cretaceous Period. 

  • Nicole Klein/Universitat Bonn
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    Next: Top 10 Scariest Sea Monsters

    The Thalattoarchon's rise demonstrates the speedy upswing and evolution of a modern ecosystem structure after extinction. "Findings like Thalattoarchon help us to understand the dynamics of our evolving planet and ultimately the impact humans have on today's environment," said Dr. Nadia Frobish of the Humboldt Museum in Berlin.