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.

Do toads have teeth?

No. A reference chapter on true toads (family Bufonidae) states that most frogs have teeth on the upper jaws, but all bufonids lack them. It adds that the absence of teeth is still a diagnostic feature of the group.

So the answer depends on the animal. Most frogs have tiny upper-jaw teeth, true toads have none, and one marsupial tree frog has teeth on both jaws.

Horned frogs and their fangs

Horned frogs, including the pet-trade Pac-Man frogs, are the best-known biters. A 2016 review in EvoDevo by Fabrezi and colleagues covers the three genera: Ceratophrys, Chacophrys and Lepidobatrachus.

Their upper-jaw teeth are simple, single-pointed and calcify early, in late larval stages. Most other frogs form two-pointed teeth at the end of metamorphosis.

The lower jaw carries robust, fang-like odontoids on each side of the chin joint. The authors describe them as fully ossified outgrowths of dermal bone that fuse to the lower jaw early in metamorphosis.

In other frogs, odontoids are thin projections of the lower jaw bone. In horned frogs the fangs are separate ossifications with their own developmental path, which the authors treat as an evolutionary novelty.

They link the fangs to capturing and subduing large, active prey. National Geographic places the fanglike teeth of Pac-Man frogs in the upper jaw, while the review stresses the lower-jaw fangs. Both describe a frog built to grip.

Tadpole mouthparts: beaks and tooth rows

Animal Diversity Web says tadpoles lack true teeth, yet tadpoles do have hard mouth structures. Herpetologist Ronald Altig describes keratinized jaw sheaths with serrated cutting edges on the upper and lower jaw cartilages.

Many tadpoles also have rows of labial teeth. Each one is a single keratinized structure formed by one cell. The rows sit on ridges on the oral disc, outside the jaws, and new teeth replace old ones that break or fall out.

Species differ widely. The most common tooth-row pattern is two upper rows and three lower rows, but counts across frogs range from none to 17 upper and 21 lower rows. Some tadpoles have an oral disc with no keratinized parts, and three families lack all of them.

The jaw sheaths are living tissue. Altig explains that sheath cells are produced continually at the base, harden with keratin as they move outward and eventually slough off. The upper sheath is usually a smooth arc, and the lower one is most often V-shaped.

Not every tadpole feeds this way. Pipid tadpoles have a long, mobile barbel at each corner of the mouth and no oral flaps. Microhylid tadpoles have hemispherical oral flaps and lack ventral lip derivatives and barbels. Some stream-dwelling and cannibalistic tadpoles have modified jaw sheaths.

How frogs swallow without chewing

Frogs do not chew. They grab prey with the tongue and jaws, then swallow it whole. A 2004 study in the Journal of Experimental Biology (Levine, Monroy and Brainerd) filmed northern leopard frogs eating crickets about 1.5 cm long.

X-ray video showed the eyes retracting deep into the throat and appearing to touch the prey. The authors describe eye retraction as an accessory swallowing mechanism that may help push food toward the esophagus.

It is not essential. After the eye-retracting muscles were denervated, frogs still swallowed. They needed more swallows per cricket, a mean of 4.0 instead of 2.3, which is an increase of 74%.

Common myths about frog teeth

• Myth: frogs chew their food. Fact: the sources describe tongue capture and whole swallowing, not chewing.
• Myth: all frogs have teeth on both jaws. Fact: only Gastrotheca guentheri is known to have lower-jaw teeth.
• Myth: toads have the same teeth as frogs. Fact: true toads have none.
• Myth: tadpoles have the same teeth as adults. Fact: they have keratin beaks and tooth rows, which are different structures.
• Myth: a frog bite is always harmless. Fact: horned frogs have bony fangs, so handling them can cause a bite.

If you keep a horned frog or any other amphibian and notice a mouth injury, ask an exotics vet. Wash your hands after any contact, as the health note above explains.

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
• Grzimek’s Animal Life Encyclopedia: True toads, harlequin frogs, and relatives (Bufonidae), accessed 13 November 2026
• Fabrezi M, et al. (2016), EvoDevo 7:5: Developmental changes and novelties in ceratophryid frogs, accessed 13 November 2026
• Altig R (2007), Herpetological Conservation and Biology 2(1): A primer for the morphology of anuran tadpoles, accessed 13 November 2026
• Levine RP, Monroy JA, Brainerd EL (2004), J Exp Biol 207:1361: Contribution of eye retraction to swallowing performance in the northern leopard frog, accessed 13 November 2026