How Long Ago Was There Real Sea Monsters?

Written by Megan Martin
Published: October 19, 2023
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When you think of sea monsters, you may think of the beasts from fantasy and fiction. However, new studies suggest that sea monsters may have roamed the Earth millions of years ago. Though, they existed in a different form than you might think.

In 1983, in Lorraine, France, scientists excavated a set of fossils that would come to change what we know about prehistoric underwater worlds. These fossils, named Lorrainosaurus after the region where they had been discovered, represented a new genus of pliosaur that scientists are just now beginning to truly understand. 

During life, these marine reptiles were massive, measuring at least 20 feet long. Although this may be small by pliosaur standards, with some individuals measuring up to 47 feet in length, Lorrainosaurus still represents an interesting emergence. That’s because scientists suspect that Lorrainosaurus was one of the first larger species of pliosaur to evolve. This species led to the later evolution of marine reptiles big enough to classify as sea monsters. These marine reptiles came to dominate the world’s oceans for around 80 million years.

Megapredators play a large role in our understanding of prehistoric ecosystems. As a result, further research into Lorrainosaurus and its large impact provides a better perspective of a world filled with “sea monsters.” One of the most significant pieces of information to arise from this study is that scientists estimate that the mega predators evolved earlier than thought.

What Is a Mega Predator?

If you search for the term “mega predator,” it can be difficult to garner exact results. However, it can be used to refer to prehistoric species, like the Lorrainosaurus and its relatives. It can also be used to describe modern species.

In all, a mega predator is just a large animal capable of impressively catching supersized prey. An example of a mega predator could include the Megalodon. Typically, mega predators are also apex predators. Another term that may be used is super-apex predator.

Megalodon vs. Mosasaurus - Megalodon



is one species that some may consider a mega predator or super predator.

©Herschel Hoffmeyer/

The photo featured at the top of this post is © andrejs polivanovs/

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About the Author

Megan is a writer at A-Z Animals where her primary focus is birds, felines, and sharks. She has been researching and writing about animals for four years, and she holds a Bachelor of Arts in English with minors in biology and professional and technical writing from Wingate University, which she earned in 2022. A resident of North Carolina, Megan is an avid birdwatcher that enjoys spending time with her cats and exploring local zoological parks with her husband.

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