Shark-like Tails Sped Ancient Sea Monsters Through Oceans

A new study finds that mosasaurs were not as slow as scholars once thought.

And that's exactly what a new study published September 10 in Nature Communications has confirmed.

A 72-million-year-old fossil specimen of Prognathodon—a genus of mosasaur—found in a Jordanian quarry in 2008 revealed fin-like soft-tissue imprints along its tail. Those imprints demonstrate that this group of ancient sea monsters possessed powerful tails similar to ones seen on sharks today, rather than the puny ones on eels or sea snakes.

Mosasaurs were aquatic reptiles that prowled the seas and freshwater streams toward the end of the age of dinosaurs, about 98 to 66 million years ago. (Related: "Freshwater Mosasaur Stirs Marine Reptile Relationships.")

Although they are fairly well represented in the fossil record, finding soft-tissue evidence for shark-like tails on these lizard ancestors isn't

DON'T MISS THE REST OF THIS STORY!
Create a free account to continue and get unlimited access to hundreds of Nat Geo articles, plus newsletters.

Create your free account to continue reading

No credit card required. Unlimited access to free content.
Or get a Premium Subscription to access the best of Nat Geo - just $19
SUBSCRIBE

Read This Next

Did this mysterious human relative bury its dead?
This new birth control for cats doesn't require surgery
How the Zoot Suit Riots changed America

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet