A surprising number of animals get through life without any teeth at all. Every living bird species is toothless, making them the largest group of toothless vertebrates on the planet. But birds are far from alone. Turtles, tortoises, baleen whales, anteaters, pangolins, and even some fish and frogs have evolved successful strategies for eating without ever chewing.
Birds: 10,000 Species, Zero Teeth
All living birds are completely toothless. With roughly 10,000 species spanning every continent, they represent the most diverse toothless vertebrate group by a wide margin. Ancient birds did have teeth, and the fossil record shows a gradual reduction in dentition across millions of years during the Mesozoic era. What replaced those teeth was a two-part system: a hard, horny beak for grabbing and breaking apart food, and a muscular gizzard for grinding it down internally.
The gizzard is essentially a second stomach with thick, powerful muscle walls and a tough lining made of a keratin-like substance. In plant-eating and seed-eating birds, paired muscles flanking the gizzard contract two to three times per minute, grinding food against small stones the bird has swallowed. In ostriches, this grinding is continuous and actually audible. The beak handles the job teeth would do at the front end, while the gizzard takes over the crushing and pulverizing that molars handle in mammals.
Turtles and Tortoises
No living turtle or tortoise has teeth. Instead, they have a beak called a rhamphotheca, a thick, horny covering over the jaw made primarily of specialized proteins called corneous beta proteins. The outer surface of the beak constantly wears down through use and is replaced by new layers growing underneath, similar to how fingernails grow. This gives turtles a perpetually sharp cutting edge.
Different species have beaks shaped for different diets. Leatherback sea turtles use their sharp beaks to grab soft, slippery prey like jellyfish. Snapping turtles have hooked beaks strong enough to shear through fish and vegetation. Herbivorous tortoises have flat, broad beaks suited for cropping grasses and leaves. The beak is remarkably effective. Turtles have been toothless for over 100 million years and thrived across freshwater, marine, and terrestrial environments.
Baleen Whales
The largest animals ever to live on Earth eat without teeth. Baleen whales, a group that includes humpbacks, blue whales, minke whales, sei whales, right whales, and bowhead whales, filter enormous volumes of water through plates of baleen instead of chewing their food. Baleen is made of keratin (the same protein in your fingernails) and hangs in racks of plates from the upper jaw. The inner edges of these plates fray into fine bristles that act as a sieve, trapping tiny prey like krill and small fish while water flows back out.
Because baleen never air dries the way keratin structures on land animals do, the plates rely on a different method for staying stiff and strong: calcification. Mineral deposits within the keratin boost its rigidity and resistance to wear, compensating for the fact that the material is permanently underwater. In some species like right whales and bowhead whales, the bristles are extremely fine, allowing them to filter very small prey. In rorqual whales like humpbacks and sei whales, the bristles are more heavily calcified and coarser.
Anteaters and Pangolins
Anteaters and pangolins both have completely toothless mouths, despite being mammals. These animals evolved independently on separate continents (anteaters in the Americas, pangolins in Africa and Asia), yet arrived at strikingly similar solutions to the same dietary challenge: eating ants and termites.
Both groups have pointed snouts, powerful front claws for ripping open insect nests, and long, flexible, sticky tongues for lapping up prey. Since they swallow insects whole, their digestive systems do the work teeth would normally handle. Pangolins have a stomach with a thick keratinized lining and hard spines in the pylorus (the lower section of the stomach) sometimes called “pyloric teeth.” These spines physically grind up insects. Pangolins also produce chitinase, an enzyme that breaks down chitin, the tough material in insect exoskeletons. This enzyme appears in their saliva, stomach, and intestines, giving them three stages of chemical digestion for a material most mammals can barely process.
Platypuses
Adult platypuses are toothless, but they aren’t born that way. Young platypuses develop rudimentary, poorly formed, rootless molar teeth that they shed about a month after leaving the nesting burrow. After that, the teeth are gone for good. In their place, platypuses develop keratinous grinding pads on both the upper and lower jaws. These rough pads work like flat millstones, crushing the aquatic insects, larvae, and crustaceans they collect from riverbeds.
Platypuses also have cheek pouches on each side of the jaw. They stuff prey into these pouches underwater, then return to the surface to chew everything against their grinding pads. Evolutionarily, the platypus lineage wasn’t always toothless. Fossil relatives from the Miocene had robust skulls with functional teeth. The shift to toothlessness happened gradually over millions of years.
Frogs (Some of Them)
Teeth in frogs are far more variable than most people realize. Out of 429 frog species examined in a comprehensive survey, 134 were entirely toothless. Tooth loss has occurred independently more than 20 times across 200 million years of frog evolution, a rate higher than in any other vertebrate group. Nearly all frogs lack teeth on the lower jaw. Only a single known species, Gastrotheca guentheri, has lower jaw teeth. Upper jaw teeth are present in some species and absent in others, and palatal teeth (small teeth on the roof of the mouth) are the most variable of all, present in about half of species surveyed.
By contrast, all salamanders and all caecilians (limbless amphibians) retain teeth. Salamanders have teeth on the lower jaw and palate across every species, and caecilians have teeth on both jaws and the palate. So when it comes to amphibians, frogs are the outliers, repeatedly losing teeth while their relatives keep them.
Toothless Fish
Most fish have teeth, but a few notable groups do not. Sturgeons have no teeth and instead use their protrusible mouths to crush prey against bony plates. Seahorses and their close relatives, pipefish, are also toothless. They feed by rapidly sucking in tiny crustaceans and plankton through their elongated, tube-shaped snouts, generating enough suction force that teeth are unnecessary. The snout acts like a pipette, drawing in prey whole.
Why Teeth Disappear
Across all these groups, tooth loss follows a pattern: teeth become unnecessary when another structure takes over their function. In birds, the beak and gizzard replaced teeth so effectively that maintaining them offered no survival advantage. In baleen whales, filter-feeding plates made individual teeth irrelevant for catching tiny, swarming prey. In anteaters and pangolins, a muscular stomach with built-in grinding structures handles insects that are swallowed whole.
Teeth are metabolically expensive. They require minerals, they wear down, they can become infected, and they take developmental time and energy to grow. When an animal’s diet and feeding strategy no longer require them, evolution tends to shed them. The result is a remarkable range of animals that eat, thrive, and in many cases dominate their ecosystems, all without a single tooth.