This mysterious frog re-evolved a full set of teeth

More than 200 million years ago, modern frogs’ ancestors lost the teeth in their lower jaws. How did Guenther’s marsupial frog regain them?

Long-limbed and sporting dramatic horns above its eyes, Guenther’s marsupial frog is a bizarre-looking amphibian from the misty cloud forests of the Andean slopes. Like other marsupial frogs this species, known as Gastrotheca guentheri, doesn’t produce free-swimming tadpoles, but rather rears its young under a flap of skin on its back.

But it has one even more puzzling trait: It possesses a full set of teeth.

Wait. Frogs have teeth? Actually, yes: Most frogs have a small number of them on their upper jaws. But virtually all 7,000 species of living frogs lack teeth along their lower jaws—except for G. guentheri.

Unfortunately, this species hasn’t been sighted since 1996—and even before then, was seldomly found or studied. There are precious few samples of

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

'World’s worst shipwreck' was bloodier than we thought
World’s first ultrasounds of wild manta rays reveal a troubling truth
Titanic was found during secret Cold War Navy mission

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