Should T. rex be 3 species? New study sparks fierce debate.

If a controversial new study is right, famous fossils such as Sue and Stan aren’t T. rex after all. But leading experts are highly skeptical.

More than 66 million years ago, a “tyrant lizard king” ruled western North America: the fearsome predatory dinosaur Tyrannosaurus rex. But how large was this monarch’s royal family? Could what we call T. rex today be composed of multiple species?

In a controversial new study in the journal Evolutionary Biology, three paleontologists argue that the fossils assigned to T. rex cluster into three different body types, which they further contend represent three separate species. In addition to T. rex, the researchers propose two new species names: T. regina and T. imperator, from the Latin for “queen” and “emperor.”

“For Tyrannosaurus, all the specimens from North America have been put into the same species, T. rex … and that’s

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