egg tooth


egg tooth
a calcareous prominence at the tip of the beak or upper jaw of an embryonic bird or reptile, used to break through the eggshell at hatching.
[1890-95]

* * *

      tooth or toothlike structure used by the young of many egg-laying species to break the shell of the egg and so escape from it at hatching. Some lizards and snakes develop a true tooth that projects outside the row of other teeth, helps the young to hatch, and then is shed. Turtles, crocodilians, and birds have an analogous horny structure that performs a similar function. The only mammal to hatch from an egg, the duck-billed platypus, also develops an egg tooth before birth.

* * *


Universalium. 2010.

Look at other dictionaries:

  • egg tooth — n. a tooth like structure on the nose or beak of young reptiles and birds used to break the egg membrane or shell at the time of hatching …   English World dictionary

  • egg tooth — egg′ tooth n. zool. a calcareous prominence at the tip of the beak or upper jaw of an embryonic bird or reptile, used to break through the eggshell at hatching • Etymology: 1890–95 …   From formal English to slang

  • Egg tooth — In some egg laying animals, the egg tooth is a small, sharp, cranial protuberance used by offspring to break or tear through the egg s surface during hatching. It is present in most birds and reptiles, and similar structures exist in monotremes,… …   Wikipedia

  • egg tooth — noun : a hard sharp prominence on the tip of the beak or nose of embryo birds and oviparous reptiles with which they break through the eggshell; also : an analogous chitinous prominence on the head of an insect * * * a calcareous prominence at… …   Useful english dictionary

  • egg-tooth — see egg burster …   Dictionary of invertebrate zoology

  • egg tooth — noun Date: 1893 a hard sharp prominence on the beak of an unhatched bird or the nose of an unhatched reptile that is used to break through the eggshell …   New Collegiate Dictionary

  • egg tooth — noun A small, sharp, cranial protuberance used by offspring to break or tear through the eggs surface during hatching …   Wiktionary

  • egg tooth — noun a hard white protuberance on the beak or jaw of an embryo bird or reptile, used for breaking out of the shell …   English new terms dictionary

  • egg tooth — /ˈɛg tuθ/ (say eg toohth) noun a calcareous point on the tip of the beak or upper jaw, by which an unhatched bird or reptile breaks through the eggshell on hatching …   Australian English dictionary

  • Egg (biology) — Bird eggs and others (click on image for key) …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.