Frog Teeth: Do Frogs Have Teeth? What Science Says

Most frogs do have teeth, but only on the upper jaw. These tiny teeth sit on the maxilla and premaxilla, while the lower jaw bone usually has none. Only one known frog, the South American marsupial tree frog Gastrotheca guentheri, has teeth on both jaws. Most frogs rely more on their tongues than their teeth to catch insects.

It is a common question, and the answer surprises many people. Frogs are not toothless, yet they are not toothy either.

This guide explains where frog teeth are, how a lower jaw lost its teeth hundreds of millions of years ago, and which frogs broke the rule. It draws on a peer-reviewed study, a museum guide and reference sites listed at the end.

How this was made: prepared with AI assistance and checked against the sources listed at the end. Images are AI-generated illustrations, not photographs of real animals or products.

Key Takeaways

• Most frogs have small teeth on the upper jaw only.
• The lower jaw bone, the dentary, usually has no teeth.
• The ancestor of modern frogs lost lower-jaw teeth more than 230 million years ago.
• Gastrotheca guentheri regained them, a finding that challenged Dollo’s law.
• Tadpoles lack true teeth, according to Animal Diversity Web.
• Frogs rely more on their tongues than their teeth to catch insects.

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Where frog teeth are

Animal Diversity Web says the dentary, which is the main bone of the lower jaw, usually lacks teeth. The maxilla and premaxilla, which form the upper jaw, are usually tooth-bearing.

National Geographic reported that most frogs have only tiny upper-jaw teeth, and that pac-man frogs are an exception with fanglike upper teeth.

The University College London museum guide agrees with the main point: the dentary has no teeth.

What the teeth do

National Geographic reports that most frogs rely more on their tongues than their teeth to capture insects. Animal Diversity Web notes that the tongue is often large and free at the back.

The sources reviewed do not give a detailed account of how often teeth are used, so we limit this section to what they state.

A lost trait: lower-jaw teeth

A 2011 study by John Wiens in the journal Evolution used a family tree of 170 amphibian species. It concluded that the ancestor of modern frogs lost lower-jaw teeth at least 230 million years ago.

Darren Naish, writing in Scientific American, also notes that virtually all anurans lack lower jaw teeth. The exception is the marsupial treefrog genus Gastrotheca.

National Geographic adds that Wiens traced tooth evolution using DNA sequences and fossils.

The exception: Gastrotheca

National Geographic says only Gastrotheca guentheri, a South American marsupial tree frog, has teeth on both jaws. The other 6,000 or so frog species lack lower-jaw teeth.

According to the Wiens abstract, the teeth were regained in the genus Gastrotheca roughly 5 to 17 million years ago. National Geographic gives about 5 to 15 million years. The ranges differ slightly, so treat the date as approximate.

Species totals also differ by source. Animal Diversity Web says more than 4,000 frog species are recognized, while National Geographic says more than 6,000. Either way, only one species is known to have lower-jaw teeth.

Why scientists care: Dollo’s law

Dollo’s law holds that a structure lost in evolution will not return. Wiens argued that the regained teeth are a clear counterexample, and that the long gap of over 200 million years is largely unprecedented.

National Geographic suggests it may be easier to re-evolve a structure the body already builds elsewhere, such as upper-jaw teeth. A researcher quoted there said natural selection alone does not explain the finding, and the reason remains unknown.

Fangs and spikes

National Geographic notes that Pac-Man frogs have fanglike upper teeth. Some carnivorous frogs have spikes on the lower jaw, but those are not true teeth, according to the same article.

Pet owners with concerns about a frog’s mouth should ask an exotics vet.

Tadpoles

Animal Diversity Web describes tadpoles as lacking true teeth.

The sources reviewed do not describe tadpole mouthparts or tooth development in more detail, so we do not go further here.

Frequently Asked Questions

Do frogs have teeth?

Most do, but only tiny ones on the upper jaw. The lower jaw bone usually has none, according to Animal Diversity Web.

Which frog has teeth on both jaws?

Gastrotheca guentheri, a South American marsupial tree frog, according to National Geographic.

Do frogs chew their food?

The sources reviewed do not describe chewing. They say most frogs rely more on their tongues than on teeth to capture insects.

When did frogs lose their lower teeth?

At least 230 million years ago, according to a 2011 study published in the journal Evolution.

Do tadpoles have teeth?

Animal Diversity Web says tadpoles lack true teeth.

Do Pac-Man frogs have big teeth?

National Geographic says they have fanglike upper-jaw teeth.

Can a frog bite hurt?

Most frogs have only tiny upper-jaw teeth. Larger predatory species may bite harder, but the sources reviewed give no injury data.

Bottom Line

Frog teeth are a small detail with a big scientific story. A trait lost for 230 million years returned in one group of tree frogs.

To keep reading, see how frogs swallow food, our frog skeleton guide and the broader frog anatomy page.

Sources

• Animal Diversity Web (University of Michigan): Anura, accessed 31 October 2026
• Wiens JJ (2011), Evolution 65(5): Re-evolution of lost mandibular teeth in frogs (abstract, University of Arizona), accessed 31 October 2026
• National Geographic: Lost teeth re-evolved in frogs (2011), accessed 31 October 2026
• Scientific American (Darren Naish): The Remarkably Weird Skeletons of Frogs, accessed 31 October 2026
• University College London Museums: Frogs and Toads, accessed 31 October 2026
• CDC: Reptiles and Amphibians, accessed 31 October 2026