Iowa was home to a terrifying 6ft-long creature that had bone-crushing jaws and lived 340 million years ago.

While T.rex is often referred to as the “King of the Dinosaurs,” a new study has revealed that an equally ferocious predator roamed the Earth millions of years earlier.

Scientists at the Field Museum in Chicago have studied the remains of Whatcheeria, a six-foot-long lake-dwelling creature that roamed Iowa 340 million years ago.

Whatcheeria had razor-sharp teeth and bone-crushing jaws that could snap the animals in half, according to the researchers.

“It probably would have spent a lot of time near the bottom of rivers and lakes, jumping around and eating whatever it wanted,” said study co-author Ben Otoo. ‘You could definitely call this thing “the T. rex of its time.”‘

To date, around 350 Whatcheeria specimens have been discovered, which are now in the Field Museum.

In their new study, the team set out to understand how the creature grew so quickly.

“If you were to see Whatcheeria in life, it would probably look like a large crocodile-like salamander with a narrow head and lots of teeth,” Mr Otoo said.

“If he really curled up, probably uncomfortably, he could fit in your bathtub, but neither you nor he would want him there.”

Whatcheeria lived underwater and was a ‘stem tetrapod’, one of the first four-legged creatures to be part of the same lineage as humans.

“Whatcheeria is more closely related to living tetrapods like amphibians, reptiles and mammals than anything else, but it falls outside of those modern groups,” said study co-author Ken Angielczyk.

“That means it can help us learn how tetrapods, including us, evolved.”

The team went through the specimens at the Field Museum to study Whatcheeria at different stages of its life and to follow its growth.

Whatcheeria had razor-sharp teeth and bone-crushing jaws that could snap animals in half, according to the researchers.

To date, around 350 Whatcheeria specimens have been discovered, which are now in the Field Museum. Pictured: Co-author Ken Angielczyk with a crate of Whatcheeria specimens behind the scenes at the Field Museum

“Looking through these fossils is like reading a storybook, and we’re trying to read as many chapters as possible by watching the juveniles grow to adulthood,” said Professor Megan Whitney, lead author of the study.

“Because of Whatcheeria’s placement on the family tree of early tetrapods, we wanted to focus on this animal and look at its storybook at different life stages.”

The team took thin slices of the thigh bones and studied them under a microscope.

“By examining how thick the growth rings are throughout an animal’s life, you can determine if the animal grows continuously throughout its life, perhaps with some temporary interruptions, or if it basically grows to reach adult size and then stop,” Mr. Otoo said. explained.

The researchers expected to find that Whatcheeria displayed slow and steady growth, much like today’s reptiles and amphibians.

However, thigh bone samples revealed that the creature grew rapidly when young, before leveling off over time.

“If you’re going to be a top predator, a very large animal, it can be a competitive advantage to grow up quickly because it makes it easier to hunt other animals and makes it harder for other predators to hunt you,” Stephanie Pierce said. , co-author of the study.

The researchers expected to find that Whatcheeria displayed slow and steady growth, much like today’s reptiles and amphibians. Pictured: Co-author Ben Otoo standing next to a life-size illustration of a large Whatcheeria specimen at the Field Museum

Samples of the thigh bone revealed that the creature grew rapidly when it was young, before leveling off over time.

“It can also be a beneficial survival strategy when living in unpredictable environments, such as the lake system that Whatcheeria inhabited, which went through periods of seasonal die-off.”

The researchers hope the findings will shed light on the evolution of early tetrapods.

“Evolution is about trying different lifestyles and combinations of traits,” added Dr. Angielczyk.

‘And so you get an animal like Whatcheeria which is an early tetrapod, but it’s also a pretty fast growing one. It is really big for its time.

“He has this weird skeleton that potentially allows him to do some things that some of his contemporaries didn’t.

“It’s an experiment in how to be a top predator, and it shows how diverse life on Earth was and still is.”