Do Walrus Have Teeth? Beyond Their Famous Tusks

Walruses do have teeth beyond their iconic tusks, though fewer than you might expect. A living adult walrus typically carries around 18 teeth in total, including the tusks, but the number varies because many teeth that develop never fully erupt or are lost early in life. The tusks themselves are simply elongated upper canine teeth, so the real question is what else is going on inside that mouth. The answer involves a set of small, peg-like cheek teeth, a powerful suction-feeding system that makes heavy chewing unnecessary, and a dental history that scientists can actually read like a diary of the animal’s life.

What a Walrus Mouth Actually Contains

The most common dental formula for an adult walrus works out to one upper incisor on each side, one canine on each side (the tusks in the upper jaw, plus a smaller lower canine), and three premolars on each side in both upper and lower jaws. That adds up to about 18 functional teeth. But the theoretical full complement is larger. Researchers examining walrus skulls have confirmed a theoretical dental formula that includes three incisors, one canine, four premolars, and two molars in each upper quadrant, with a slightly different count on the lower jaw, for a total that could reach into the mid-twenties.¹ In practice, none of the specimens in that study possessed a full set of theoretically possible teeth. Most of those extra incisors and molars simply never erupt or are resorbed before adulthood.

The teeth that do show up are small and flat-topped compared to those of other carnivores. They look more like blunt pegs than the sharp, pointed teeth you would find in a seal or sea lion. This makes sense when you consider how a walrus eats: it does not bite and tear prey the way a leopard seal does. Instead, it uses suction to vacuum clams and other soft-bodied invertebrates right out of their shells. The cheek teeth serve more as a backstop and processing surface than as cutting tools.

Walruses also go through two sets of teeth during their lives. The deciduous (baby) set includes 28 teeth, with a full row of incisors and milk molars on each side.² These are replaced by a successional set that is already reduced compared to the baby teeth, and the functional adult set is smaller still. It is a progressive simplification: each stage of life carries fewer teeth than the one before.

Those Tusks Are Canines, Not a Separate Category

The tusks that define the walrus silhouette are simply the upper canine teeth, grown to extreme proportions. Both males and females have them, though male tusks tend to be longer and heavier. The tusks are classified as aradicular hypsodont, meaning they grow continuously throughout the animal’s life without developing true roots. Longitudinal grooves run along the outer and inner surfaces of each tusk, and these grooves help anchor the tusk securely within its socket in the skull.

Structurally, a walrus tusk is made mostly of dentine, the same material that forms the bulk of your own teeth beneath the enamel. In tusks, this dentine core is what we call ivory. Surrounding it is a thin layer of cementum, which is a sofite derivative of enamel. Unlike elephant ivory, walrus ivory has a distinctive internal grain pattern visible in cross-section, sometimes described as looking like marbled or oatmeal-textured material.³ The dentine itself is made up of particles roughly 5 to 20 micrometers across, embedded in a ground substance threaded with tiny tubules. This microstructure gives walrus ivory its characteristic feel and workability, which is different from elephant ivory and has been prized by Arctic peoples for thousands of years.

Male tusks are not just bigger; they also show more asymmetry between left and right. A study of Pacific walrus tusk measurements spanning more than two decades found that males exhibited about 40% greater fluctuating asymmetry than females.⁴ Fluctuating asymmetry is a measure of how different the left and right sides are from each other, and higher values can reflect developmental stress. The fact that males show more of it may relate to the heavier energetic demands of growing larger tusks while also competing for mates.

Why So Few Teeth for a Carnivore

Walruses belong to the order Carnivora, the same group that includes wolves, bears, and cats, all animals known for elaborate and sharply differentiated teeth. So why has the walrus shed most of its dental toolkit? The answer lies in its feeding strategy. A walrus does not need to slice meat or crack bones. Its primary food consists of clams, mussels, snails, and other benthic invertebrates that it excavates from the sea floor. To eat a clam, the walrus positions its mouth over the prey, seals its thick lips around the shell, and retracts its tongue with enormous force to create suction that rips the soft body right out.

Researchers have modeled this tongue retraction in detail, examining the forces generated by the major tongue muscles during suction feeding. The supported model shows the tongue moving directly backward along the curve of the palate, and this movement creates enough negative pressure to extract prey from shells efficiently.⁵ The study also found wear striations on the palatal and tongue-side surfaces of the teeth that matched this backward retraction pattern, meaning the tongue is physically grinding against the teeth during feeding. Those flat, peg-like cheek teeth make more sense in this context: they are not biting tools so much as surfaces the tongue works against.

This suction-based system means the cheek teeth experience a very different kind of wear than you see in predators that chew. Rather than sharp cusps being ground down by bone or gristle, the walrus’s teeth are slowly polished by repeated contact with the muscular tongue and the grit of bottom sediment. Over a lifespan that can reach 30 to 40 years, this adds up. Older walruses often have teeth worn nearly flat.

What Happened to the Enamel

Modern walrus teeth are sometimes described as lacking enamel entirely, but the evolutionary picture is more nuanced. A study comparing the enamel microstructure of fossil and living pinnipeds found that despite the overall simplification in tooth shape and reduced chewing that comes with aquatic life, modern pinnipeds retained complex enamel structures inherited from their terrestrial carnivore ancestors.⁶ The undulating enamel pattern found in these pinnipeds matches what is seen in other living members of Carnivora, even though many marine mammals, like whales, independently evolved much simpler enamel or lost it altogether.

In living walruses, any enamel that does form on the cheek teeth is thin and tends to wear away quickly. The tusks develop a cementum coating rather than a substantial enamel layer. But the fact that the underlying genetic blueprint for complex enamel persists is a reminder that walrus dental simplification is relatively recent in evolutionary terms. Their ancestors had more elaborate teeth suited to different diets, and the shift toward suction feeding and benthic foraging drove the reduction we see today.

Dental Problems in Walruses

Given how few teeth a walrus carries and how hard those teeth work, you might expect dental disease to be common. In fact, the majority of walrus teeth appear normal. In a pathology study that surveyed walrus skulls, only about 0.6% of available teeth were malformed.¹ That is a strikingly low rate of obvious abnormality. However, the same study did examine broader jaw and joint pathology, and the temporomandibular joint (the jaw hinge) showed more frequent issues, which makes sense for an animal that generates extreme suction forces thousands of times a day over decades.

Tusk breakage is another concern. Walruses use their tusks for hauling themselves out of the water onto ice, for display and sparring with rivals, and for maintaining breathing holes in ice. A broken tusk is not just a cosmetic problem; it can expose the pulp cavity to infection. Captive walruses sometimes develop tusk problems from contact with enclosure surfaces, and veterinary management of tusk health is a significant part of walrus husbandry in zoos and aquariums.

Teeth as Environmental Records

One of the more remarkable uses of walrus teeth has nothing to do with the animal itself and everything to do with what the teeth can tell us about the Arctic environment. Like tree rings, walrus teeth lay down annual growth layers in their cementum. Each layer corresponds roughly to one year of the animal’s life, and the chemical composition of each layer reflects what the walrus was eating and what contaminants it was exposed to during that period.

Researchers have used these growth layers to reconstruct lifetime histories of trace element exposure for individual walruses. By measuring elemental concentrations across cementum growth layer groups, scientists can associate each layer with a specific age and calendar year, effectively turning a single tooth into a decades-long record of environmental conditions.⁷ The results suggest that while the animal’s own physiology does influence which elements end up in the tooth, many trace elements genuinely reflect environmental exposure and dietary intake. In other words, the tooth is not just recording the walrus’s internal chemistry; it is recording what was happening in the ocean around it.

Earlier work using laser ablation techniques demonstrated that metals like lead, copper, zinc, and strontium could be detected in repeatable patterns within individual annual growth layers of walrus teeth harvested from the Canadian Arctic.⁸ The resolution was fine enough to pinpoint metal exposure to within a single year of the animal’s life. Because walruses can live for decades, a series of teeth from animals of different ages can be stitched together to assemble pollution histories stretching back a century or more. For researchers monitoring contaminant trends in a rapidly changing Arctic, walrus teeth are among the best long-term biomonitors available.

Walrus Ivory in Human History

The dense, workable nature of walrus tusk dentine made it one of the most important raw materials in the pre-industrial Arctic. Archaeological evidence shows that early Arctic peoples were using walrus ivory for tool production as far back as roughly 2500 BCE. During the Pre-Dorset period, walrus use was almost entirely focused on scavenging ivory from carcasses rather than hunting live animals for meat.⁹ The homogeneous nature of primary dentine means it can be flaked in a way similar to stone knapping, but it can also be grooved, carved, whittled, and abraded using techniques more like ground-stone work. That versatility made ivory a uniquely flexible material.

Walrus ivory later became a major trade commodity. During the medieval period, Norse settlers in Greenland exported walrus tusks to European markets, where the ivory was used for chess pieces, religious carvings, and luxury goods. The famous Lewis Chessmen, discovered in Scotland and dating to the twelfth century, are carved primarily from walrus ivory. For communities across the Arctic, from Inuit groups in Canada to Yupik peoples in Alaska and Chukchi peoples in Siberia, walrus ivory carving remains a living cultural tradition. The material’s grain, hardness, and ability to take fine detail make it distinct from elephant ivory, and experienced carvers can identify walrus ivory by its cross-sectional texture alone.

What Walrus Teeth Reveal About Pinniped Evolution

The walrus is the sole surviving member of its family, Odobenidae, but the fossil record shows that the family was once much more diverse. Some extinct walrus relatives had dramatically different dentition, including species with well-developed cheek teeth suited for processing fish or even other marine mammals. The retention of complex enamel microstructure in modern pinnipeds, including the walrus lineage, suggests that the simplification of walrus teeth happened after the group had already evolved the underlying enamel architecture shared by land-dwelling carnivores.⁶ The contrast with whales is instructive: toothed whales independently evolved much simpler, peg-like teeth for catching fish, and their enamel reflects that separate evolutionary path. Walruses arrived at superficially similar-looking simple teeth through a completely different route, driven by suction feeding on the sea floor rather than fish pursuit in open water.

One extinct relative, Pelagiarctos, had teeth robust enough to suggest it may have been a macropredator, eating large prey rather than bottom-dwelling invertebrates. The fact that both macropredatory and suction-feeding ecologies evolved within the same family shows how flexible pinniped dentition can be. The modern walrus’s reduced, peg-like teeth are not a sign of some evolutionary dead end but rather a highly specialized solution to a specific ecological niche. Every lost incisor and vestigial molar is a trace of that specialization, visible in the skull of every walrus alive today.