Skip to main content

Animal lists · 12 entries

Animals That Can Regrow Teeth

Polyphyodont animals — including sharks, crocodiles, geckos and most fish — replace teeth throughout life, with sharks growing tens of thousands over a lifetime from rotating tooth rows, while mammals almost universally have only two sets (diphyodont) at most.

Updated 25 July 2026

Humans get two sets of teeth — milk and adult — and no more. Many animals replace teeth continuously throughout life, a condition called polyphyodonty. Sharks are the extreme case, with conveyor-belt rows replacing teeth every few weeks.

This list covers animals with documented continuous or multiple tooth replacement, noting the mechanism and approximate replacement rate where known. Mammals are largely excluded because diphyodonty — two sets only — is the mammalian norm.

How this list was compiled

Entries are species with documented continuous (polyphyodont) or multiple tooth replacement beyond the standard two sets of mammals. Replacement rate and mechanism — rotating rows, sequential eruption, whole-jaw replacement — are noted. Mammals with only two sets (diphyodont) are excluded unless they show exceptional replacement such as elephants growing new molars. Single anecdotal reports are flagged.

Animals That Can Regrow Teeth

  1. Shark

    Continuous; ~20,000–30,000 lifetime

    Conveyor-belt rows move forward as front teeth are lost. New teeth ready within days.

  2. Crocodile

    Continuous; ~3,000 lifetime

    Each tooth socket holds replacement teeth beneath the active tooth. Replaced every few months.

  3. Gecko

    Continuous replacement

    Polyphyodont — teeth replaced throughout life. Each tooth has a replacement developing in the jaw beneath it.

  4. Most fish

    Continuous replacement

    The majority of fish species replace teeth continuously. Rate varies from weekly to annually by species.

  5. Snake

    Regular replacement

    Fangs and teeth replaced periodically. Venom fangs are replaced every few weeks in vipers.

  6. Elephant

    Six sets of molars over lifetime

    Not continuous but multiple — molars migrate forward and are replaced up to six times. Final set typically worn out by the 60s.

  7. Manatee

    Continuous molar replacement

    Molars migrate forward in the jaw as new ones erupt at the back — sometimes called marching molars.

  8. Dolphin

    Single set; no replacement

    Included as contrast — cetaceans have one set of teeth with no replacement. Tooth loss is permanent.

  9. Alligator

    Continuous; ~2,000 lifetime

    Similar crocodilian mechanism. Can replace each tooth up to 50 times over a long life.

  10. Piranha

    Continuous; interlocking rows

    Razor-sharp teeth replaced in interlocking rows throughout life. Critical for feeding on flesh.

  11. Komodo dragon

    Regular replacement; serrated

    Teeth are serrated and replaced regularly. Combined with anticoagulant saliva in hunting.

  12. Rodent (incisors)

    Continuous incisor growth

    Incisors grow continuously from open roots and are worn down by gnawing — not replacement but continuous growth achieving the same functional outcome.

Key facts

  • Sharks replace teeth continuously from rotating rows — up to 30,000 over a lifetime.
  • Polyphyodonty — continuous tooth replacement — is the ancestral condition; mammalian diphyodonty (two sets) is the exception.
  • Crocodilians and alligators replace each tooth up to 50 times, with replacements developing beneath active teeth.
  • Elephants grow six sets of molars over a lifetime — not continuous but the most replacement of any mammal.
  • Rodent incisors grow continuously from open roots — functionally equivalent to replacement without shedding.
  • Cetaceans have a single non-replaced set of teeth — tooth loss is permanent and visible in older dolphins.

Animals That Can Regrow Teeth: frequently asked questions

Which animals can regrow teeth?
Sharks, crocodiles, alligators, geckos, most fish and snakes replace teeth continuously throughout life. Elephants grow six sets of molars. Rodents grow incisors continuously.
Do sharks regrow teeth?
Yes, continuously. Conveyor-belt rows of replacement teeth move forward as front teeth are lost. A shark may use 20,000 to 30,000 teeth in a lifetime.
Can humans regrow teeth?
No. Humans are diphyodont — two sets only. Milk teeth are replaced by adult teeth and no further replacement occurs. Research into stem cell tooth regeneration is ongoing but not clinically available.
Do crocodiles regrow teeth?
Yes. Each socket holds replacement teeth beneath the active one. A crocodile may replace each tooth up to 50 times over its life — roughly 3,000 teeth total.
How many sets of teeth do elephants get?
Six sets of molars over a lifetime. New molars erupt at the back of the jaw and migrate forward as older ones wear out. The final set is typically exhausted by the elephant's 60s.
Why can some animals regrow teeth but mammals mostly cannot?
Polyphyodonty is ancestral. Mammals evolved diphyodonty — two sets — likely because precise tooth fit for chewing mattered more than continuous replacement. The genetic pathways for regeneration still exist but are largely switched off.

Sources

How we check facts: our sourcing standards →

More animal lists

All animal lists Animals A–Z
Donate