Teeth are hard structures in the mouths of many animals that are used for biting, catching, and chewing food. Teeth allow animals to mechanically break down and digest their food. Most teeth have a crown above the gumline and roots embedded in the jawbone. The crown is covered in hard enamel, while the root is covered in cementum. Teeth are made up of different tissues, like enamel, dentin, cementum and dental pulp.
What are the different types of teeth?
There are four main types of teeth in mammals:
- Incissors – These teeth are shaped like chisels and used for cutting or biting off pieces of food.
- Canines – These are pointed teeth used for tearing food.
- Premolars – These teeth have cusps and are used for crushing and grinding food.
- Molars – These teeth are flat and have cusps used for grinding food.
Humans have two sets of teeth in their lifetimes. The first set of 20 baby teeth start coming in around 6 months of age. The adult set of 32 permanent teeth replace the baby teeth starting around age 6.
What animals have teeth but cannot bite?
There are some animals that have teeth but lack the ability to deliver an actual bite:
- Whales – Whales have teeth but their jaws are not structured in a way that allows them to bite down hard. They use their teeth to filter feed.
- Anteaters – Anteaters have small teeth compared to the size of their mouths. Their tongues are their main tool for eating insects.
- Pangolins – Pangolins have teeth but barely use them because their diet consists mainly of ants and termites which they lap up with their long tongues.
- Aardvarks – Aardvarks have teeth but swallow their insect prey whole, so they don’t use their teeth to chew.
- Platypus – Platypuses have teeth but no enamel coating, so they cannot bite hard enough to chew. They use their teeth to hold prey while they tear soft pieces with their jaws.
- Echidnas – Spiny anteaters like echidnas have tiny spikes on their tongues and toothless jaws suited for eating ants whole.
- Baleen whales – Baleen whales have baleen plates to filter feed instead of teeth designed for biting or chewing.
- Sturgeon – Sturgeon have toothlike structures called denticles but lack true teeth and jaws for biting.
- Loaches – Many small fish like loaches have tiny teeth not designed for biting, just holding prey.
- Crustaceans – Crustaceans like crabs and lobsters have teeth-like structures within their stomachs for grinding up food after swallowing it whole.
Why do some animals have teeth but minimal biting ability?
There are several evolutionary reasons why some animals retain teeth but have minimal ability or need for biting:
- Diet – Animals that swallow their food whole or filter feed have less need for biting and chewing. Teeth can still assist with initial prey capture.
- Anatomy – Some animals have mouths and jaw structures not suited for forceful biting, even if they have teeth.
- Vestigial features – Rudimentary teeth may be vestigial evolutionary holdovers that no longer serve a function.
- Specialized roles – Teeth may serve specific purposes like grasping prey or displaying but provide little biting function.
- Mechanical limitations – Lack of tooth enamel or jaw muscles can prevent effective biting force generation.
Having teeth but losing biting abilities is common in animals that transition to new food sources or feeding methods over evolutionary time. Retaining some minimal tooth structures still offers advantages for grasping food even if biting force is greatly reduced.
What are some examples of animals with teeth but no bite ability?
Baleen Whales
Baleen whales like humpback and blue whales have baleen plates in their mouths instead of teeth. Baleen is made of keratin and hangs from the whale’s upper jaw in long sheets. It acts as a filter, allowing the whale to scoop up thousands of gallons of water and prey inside its mouth. The baleen plates trap small fish, krill, and plankton while the water drains out. While baleen whales lack biting teeth, they still have leftover vestigial teeth embedded in their gums that never break through the surface.
Anteaters
Anteaters like the giant anteater have tiny peg-like teeth compared to their long snouts and huge tongues. They use their tongues to lap up thousands of ants and termites a day from nests and mounds. Their tooth structure provides no real ability to bite or chew prey. Instead, they swallow their insects whole and digest them internally. Their teeth likely help grip prey while their tongue brings it into the mouth.
Sturgeon
Sturgeon are toothless bottom feeders with bony plates called scutes for protection. They have sensory barbels by their mouths to locate prey on river bottoms. While sturgeon lack true teeth, they have tooth-like spike structures called denticles. These bony denticles line their mouths and assist with grasping slimy prey items. However, sturgeon have no capacity for biting as they are not true teeth with roots. Their diet of worms, crustaceans and mollusks requires no biting or chewing.
Aardvarks
Aardvarks have teeth but use their long sticky tongues to lap up thousands of insects like termites whole each night. Their teeth are useless for biting or chewing due to their habits. However, they still retain teeth likely as an evolutionary remnant from insect-eating ancestors. Their tooth crowns lack decent enamel and exhibit heavy wear from use as temporary grips for their tongues. Overall their teeth serve minimal function given their dietary needs.
Platypuses
Platypuses have leathery toothless jaws but retain horny spike plates for male competition. They lack molars and premolars, indicating evolutionary loss of chewing function. However, adult platypuses have ridges and spurs along their jaws that resemble remnant teeth. They likely use these spikes to grip slippery prey like worms and crayfish. But their tooth structures provide no real biting or chewing ability.
How do animals like crabs bite without teeth?
Crabs and other crustaceans have mouthparts and claw pincers suited for biting despite lacking teeth. Their biting ability comes from sharp appendages rather than teeth:
- Pincers – The front claws pinch and tear prey into bite-size pieces for the mouth.
- Mandibles – Hard mouthparts containing chitin crush and grind food.
- Gastric mill – The stomach has tooth-like structures called ossicles for mechanically digesting food once swallowed.
Without molars or incisors, crustaceans rely on exterior claws and interior gastric mills to provide biting, chewing, and crushing functions. This allows them to generate considerable bite force without the need for teeth inside the mouth itself.
Do snakes have teeth but lack biting ability?
No, all snakes are capable of biting using their teeth. Snake teeth are curved backwards and very sharp, designed for puncturing, gripping, and envenoming prey. While tooth shape varies among species, all snakes have flexible jaws allowing them to open their mouths very wide to sink their teeth into prey. Venomous snakes especially rely on their teeth to deliver potent venom when they bite. Various snakes have teeth adapted for specific diets:
- Long front fangs – Vipers and elapids for injecting venom.
- Gripping rear teeth – Pythons and boas for holding prey.
- Small hooked teeth – Insect-eating snakes like vipers for grasping.
Overall, snakes are extremely effective and lethal biters. Their flexible skulls maximize the biting capacity of their sharp teeth. No snakes lack the ability to bite using their specialized dentition.
Do sharks bite even without teeth?
Yes, sharks can definitely still bite without teeth, just with less efficiency. Sharks continually shed their teeth throughout life and regrow replacements. So they are adapted to function despite missing some teeth at times. Shark teeth are arranged in multiple rows within the mouth, ensuring backup teeth for biting if some are lost. Major bite power comes from shark jaw and head muscles, not just teeth alone. Some ways sharks can bite without teeth:
- Remaining teeth – Sharks have multiple tooth rows, so adjacent teeth can still pierce prey.
- Toothless jaws – Shark jaws themselves produce significant clamping force for holding prey.
- Head shaking – Sharks shake their heads violently to saw through prey with serrated edges on their jaws.
In general, sharks are able to compensate for missing teeth using other specialized adaptations. But tooth loss does decrease their feeding effectiveness until replacements grow in.
Do sponges have teeth?
No, sponges do not have teeth or any other hard biting structures. As very simple aquatic invertebrates, sponges lack proper tissues or organs. They draw water into pores all over their body for filter feeding. Tiny hair-like structures called choanocytes filter out food particles as the water gets pumped through the sponge. Being immobile filter feeders, sponges have no need for teeth or biting mouthparts. Some sponges do have internal spicules made of silica or calcium carbonate that help structurally support their soft bodies. But sponges completely lack teeth or any kind of jaws or mouth to bite with. They are toothless filter feeders.
Can starfish bite? Do they have teeth?
Starfish cannot bite and completely lack teeth or jaws. As echinoderms, starfish have a very simple decentralized body plan without a head or mouth for biting. Instead, starfish extend their stomach out of their body through their mouth on the underside to digest prey. Tiny tube feet surrounding the mouth help maneuver food inside. Once prey is restrained by the tube feet, the stomach envelops around it and secretes digestive enzymes to break down food externally. This process is called extracellular digestion. Their tube feet have suckers but no tooth-like structures. The mouth itself is toothless and only used to evert their stomachs. Starfish are unable to actively bite or chew food like species with teeth and jaws can.
Do worms have teeth?
Most worms lack any form of teeth or jaws for biting because they swallow food whole or absorb nutrients through their skin. However, some aquatic worms have tooth-like structures:
- Polychaete worms – Jawed species like eunicids have sharp mandibles for biting off food.
- Peanut worms – sipunculids have hardened mouthparts for scraping prey.
- Bristle worms – polychaetes have chitinous jaws and can deliver a pinch when handled.
These worms use their tooth-like mouthparts to scrape algae off rocks, capture prey, or tunnel through sediment. But most earthworms and leeches lack jaws or teeth and ingest dirt, microorganisms, or bodily fluids. Overall, teeth appear sporadically in select worm groups but are absent in most worm species.
Do lobsters have teeth in their stomachs?
Yes, lobsters have tooth-like structures called gastric mills located in their stomachs. These calcified ossicles consist of three grinding surfaces that mash food against each other. The gastric mill contains two lateral teeth plates that move against a central median tooth. Muscles control the ossicles to crush food between these three surfaces within the stomach organ itself. Having teeth internally allows lobsters and other crustaceans to shred their food after swallowing it whole. Chewing occurs through the mechanical motion of their gastric mills rather than teeth inside the mouth. These ossicles give lobsters teeth-like chewing capacity without jaws or molars for active biting.
Do all animals with teeth bite?
No, there are some examples of animals with teeth that lack enough jaw strength or biting ability to effectively use their teeth:
- Fish – Small carp and aquarium fish have tiny non-functional teeth not made for biting.
- Turtles – Turtles have beaks for biting with toothless jaws; Only snapping turtles have reduced teeth for chewing, not biting.
- Anteaters – Long snouts and tooth structure prevent strong bite force despite having simple teeth.
- Waterfowl – Geese and ducks have lamellae edged bills but no biting teeth inside their mouths.
- Baleen whales – Vestigial useless teeth are embedded in gums but serve no purpose.
For these animals, teeth serve incidental purposes like grasping food but minimal or no real biting function. Jaw anatomy, tooth shape, and dietary needs make active biting and chewing unnecessary despite some residual tooth presence.
Conclusion
In summary, teeth primarily serve a biting and chewing function for mechanically processing food in many animals. However, examples like baleen whales, anteaters, sturgeon, and crabs illustrate species that retain vestigial teeth or tooth-like structures even though they lack biting capacity or need. Teeth can serve supplemental purposes like grasping, filtering, or displaying even without strong bites. Jaw structure, tooth shape, enamel presence, and dietary needs all influence how animals use their teeth. While teeth imply biting potential in most species, some animals intriguingly have teeth but cannot or do not bite, showing teeth alone do not define biting ability.
