Do whales have teeth?

Quick Answer

Do whales have teeth? The scientific answer is yes, but not all of them, and not always in the way we expect. Biologists classify whales into two distinct parvorders based primarily on their feeding anatomy: Odontoceti (toothed whales) and Mysticeti (baleen whales).

Toothed Whales (Odontocetes): This group includes the Sperm Whale, Killer Whale (Orca), Narwhal, and all dolphins and porpoises. They possess hard, enamel-coated teeth designed for grasping, tearing, or sensing, rather than chewing. For example, a sperm whale can have up to 52 teeth, while some dolphin species possess over 100.

Baleen Whales (Mysticetes): Giants like the Blue Whale and Humpback Whale do not have functional teeth as adults. Instead, they have hundreds of flexible plates called baleen—made of keratin, the same protein as human fingernails—hanging from their upper jaws. However, a fascinating evolutionary fact is that baleen whale embryos do develop tooth buds while in the womb. These buds are reabsorbed (vestigial structures) before the calf is born, providing irrefutable evidence of their descent from toothed ancestors.

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Detailed Explanation

To fully understand whale dentition, we must explore the evolutionary divergence that occurred approximately 34 million years ago. The order Cetacea (whales, dolphins, and porpoises) split into two distinct lineages that solved the problem of “how to eat underwater” in radically different ways.

The Odontocetes: Masters of the Grasp

The suborder Odontoceti (from the Greek odontos meaning “tooth” and ketos meaning “whale”) comprises roughly 75 species, making up the vast majority of cetaceans.

Structure and Function

Unlike terrestrial mammals that possess heterodont dentition (different types of teeth like incisors, canines, and molars for processing food), most toothed whales have homodont dentition. This means their teeth are uniform in shape—typically conical or peg-like.

Because whales cannot chew their food (they lack the lateral jaw movement required for grinding), their teeth serve a singular, lethal purpose: prehension. This is the biological term for grasping and holding onto slippery, struggling prey like squid, fish, or other marine mammals. Once captured, the prey is usually maneuvered and swallowed whole.

The Anatomy of these teeth varies significantly between species:

• Conical Teeth: Found in orcas and sperm whales, these are thick and strong, designed to withstand the thrashing of large prey.
• Spade-Shaped Teeth: Porpoises generally have flattened, spade-like teeth, distinct from the conical teeth of dolphins.
• Reduced Dentition: Some species, particularly beaked whales, have lost almost all their teeth. In many beaked whale species, only the males possess a single pair of tusks that erupt from the gum line, primarily used for combat over females rather than feeding. These whales feed by suction, slurping up squid, rendering functional teeth unnecessary for dietary purposes.

The Monophyodont Trait

Most mammals are diphyodont, meaning they have a set of “baby teeth” (deciduous) followed by a permanent set. Toothed whales are monophyodont—they grow one set of teeth that must last their entire lives. If a Killer Whale breaks a tooth, it does not grow back. This makes dental health critical for their survival, although researchers have observed healthy wild whales with teeth worn down to the gums, suggesting that for cooperative hunters, teeth may be optional for survival if the pod assists in feeding.

The Mysticetes: The Great Filterers

The suborder Mysticeti (baleen whales) includes the largest animals to ever live. They have traded teeth for a highly efficient filtration system that allows them to consume massive quantities of calories with minimal energy expenditure.

From Teeth to Baleen

Evolutionarily, the ancestors of baleen whales had teeth. The fossil record shows transition species like Janjucetus which possessed both teeth and wide jaws suitable for suction feeding. Over millions of years, the teeth became smaller and eventually vanished, replaced by baleen.

Today, this history is replayed during gestation. A fetal Gray Whale or Fin Whale will develop tooth buds along its jawline. As the fetus matures, these buds are reabsorbed into the body, and the gum tissue thickens and keratinizes to form the baleen plates. This is a classic example of “ontogeny recapitulating phylogeny”—the development of the individual mirrors the evolution of the species.

Mechanism of Baleen

Baleen hangs in rows from the upper jaw, resembling a comb or a stiff brush. The plates are arranged somewhat like the slats of a Venetian blind.

1. The Plates: Flat, flexible sheets of keratin.
2. The Fringes: The inner edge of each plate is frayed into coarse bristles.
3. The Process: The whale engulfs a massive volume of water and prey (krill, copepods, small fish). It then pushes the water out through the baleen using its massive tongue. The water escapes, but the prey is trapped in the bristles, ready to be swallowed.

For more on what these giants consume, read our guide on what do whales eat.

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Comparative Analysis: Dental Anatomy Across Species

The diversity in whale “teeth” is staggering. Below is a detailed comparison of how dentition (or the lack thereof) dictates the lifestyle, diet, and behavior of different whale species.

Comparison Table: Teeth vs. Baleen

Species	Classification	Dental Structure	Count	Primary Function	Prey Type
Sperm Whale	Odontocete	Conical, ivory teeth (mostly lower jaw)	20-26 pairs	Grasping giant squid; combat between males	Squid, Sharks, Skates
Killer Whale	Odontocete	Large, interlocking conical teeth	10-14 pairs per jaw	Tearing and gripping large prey	Seals, Fish, Whales, Squid
Narwhal	Odontocete	Modified canine tooth (Tusk)	Usually 1 (males)	Sensory organ; social dominance	Halibut, Cod, Squid (suction feeder)
Blue Whale	Mysticete	Baleen plates (Black keratin)	270-395 plates per side	Filtering krill from water	Krill (exclusively)
Bowhead Whale	Mysticete	Longest baleen plates of any whale	Up to 600 plates	Continuous skimming	Zooplankton, Copepods
Cuvier’s Beaked Whale	Odontocete	Modified tusks (tip of jaw)	2 (males only)	Combat; mostly vestigial for feeding	Squid (suction feeder)

Specific Evolutionary Marvels

The Narwhal: The Tooth That Became a Sensor

The Narwhal possesses perhaps the most unique tooth in the animal kingdom. Often called the “unicorn of the sea,” the male narwhal’s tusk is actually an elongated left canine tooth that spirals counter-clockwise, growing up to 10 feet long through the whale’s upper lip.

• Sensory Input: Recent research indicates this tooth is filled with millions of nerve endings. It acts as a hydrodynamic sensor, detecting changes in water temperature, pressure, and salinity, and perhaps even locating fish.
• Not for fighting? While historically thought to be a spear, it is rarely used violently. It is more likely a visual signal of fitness to females and a sensory tool.

The Sperm Whale: Ivory Hunters

The Sperm Whale is the largest toothed predator on Earth. However, its teeth are a biological puzzle.

• Lower Jaw Only: They possess functional teeth only on their bottom jaw. The upper jaw contains sockets for these teeth to fit into.
• Delayed Eruption: A sperm whale’s teeth often do not erupt from the gums until the whale reaches sexual maturity (around 10-20 years old). This suggests the teeth may play a role in social dominance or mating as much as feeding. Since sperm whales have been found with healthy stomachs but no teeth, it is believed they use suction to capture giant squid, using the teeth merely to secure the initial grip.

The Killer Whale: The Ultimate Weapon

Unlike the sperm whale, the Killer Whale uses its teeth aggressively. Their teeth interlock perfectly when the jaw closes.

• Wear and Tear: Scientists can determine the diet of specific orca populations by looking at tooth wear. “Offshore” orcas that eat sharks often have teeth worn flat to the gum line due to the abrasive shark skin. “Resident” orcas that eat salmon typically have sharper teeth, though still subject to wear over decades.

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Why This Matters

Understanding whether whales have teeth or baleen is not just a trivia fact; it is fundamental to marine biology, conservation, and our understanding of ocean health.

1. Conservation and Vulnerability

The feeding mechanism determines the threat. Baleen whales, as filter feeders, are highly susceptible to microplastic ingestion. When a Fin Whale filters 70,000 liters of water in a single mouthful, it inadvertently traps plastic debris in its baleen bristles. Conversely, toothed whales face different threats. Because they occupy a higher trophic level (eating fish that eat smaller fish), they are subject to biomagnification of toxins. Heavy metals like mercury and PCBs accumulate in the blubber and can cause tooth decay and immune system failure in species like the Pilot Whale and Orca.

2. Ecological Impact

The division between toothed and baleen whales shapes the ocean’s food web.

• Top-Down Control: Toothed whales regulate populations of seals, squid, and large fish.
• Nutrient Cycling: Baleen whales, by consuming massive amounts of krill and excreting nutrient-rich plumes (fecal matter), fertilize the ocean surface, promoting phytoplankton growth. This is known as the “whale pump.”

3. Scientific Research & Aging

Teeth are the “black box” of a whale’s life.

• Dentine Layers: In toothed whales, scientists can estimate age by counting the Growth Layer Groups (GLGs) in a cross-section of a tooth, similar to counting tree rings. This allows researchers to monitor population health and longevity. See more on how long do whales live.
• Chemical Analysis: Isotopes locked in whale teeth can reveal where the whale has traveled and what it ate at different stages of its life, providing a chemical map of ocean changes over decades.

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Frequently Asked Questions

Do blue whales have teeth?

No, adult blue whales do not have teeth. As members of the suborder Mysticeti, they possess baleen plates used to filter krill. However, like all baleen whales, they do possess tooth buds during their fetal development stage, which disappear before birth. For more on their size and biology, read how big is a blue whale.

Do whales chew their food?

No, whales generally do not chew. Toothed whales (Odontocetes) use their teeth to grab, tear, or reposition prey so it can be swallowed whole. Baleen whales filter small organisms and swallow them in mass. Whales lack the lateral (side-to-side) jaw movement necessary for grinding food.

How many teeth does a shark have compared to a whale?

This is a common comparison. While a shark may grow and discard over 30,000 teeth in a lifetime (polyphyodonty), toothed whales only have one set of teeth for their entire life (monophyodonty). If a whale loses a tooth, it is gone forever.

Are there any whales with both teeth and baleen?

Not in modern times. However, the fossil record contains extinct ancestors like the Aetiocetus which possessed both functional teeth and early baleen structures, showing the evolutionary bridge between catching prey and filtering it.

What are “vestigial teeth”?

Vestigial teeth are teeth that form biologically but serve no function and may not even erupt from the gums. Some beaked whales have small vestigial teeth that never break the surface. Baleen whale embryos also have vestigial tooth buds that are reabsorbed.

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Sources and Further Reading

To ensure accuracy, this article relies on data from leading marine science organizations.

• NOAA Fisheries: The National Oceanic and Atmospheric Administration provides authoritative data on marine mammal protection and species classification. Their detailed species profiles confirm dentition counts and feeding behaviors.
• Smithsonian National Museum of Natural History: The “Ocean Portal” offers deep dives into the evolution of whales, specifically the transition from land mammals to marine dwellers, documenting the shift from teeth to baleen.
• Whale & Dolphin Conservation (WDC): As a leading global charity, WDC provides field observations regarding the feeding habits and social structures of both odontocetes and mysticetes.
• National Geographic: Provides photographic evidence and behavioral studies, particularly regarding the hunting techniques of killer whales and the sensory capabilities of narwhal tusks.

Internal Resources

For more information on whale biology, explore our guides on Whale Behavior and Whale Sounds & Songs. If you are interested in the specific diet of these giants, read what do killer whales eat and what do whale sharks eat (note: whale sharks are fish, not whales, but their filter-feeding is a great comparison!).