Definitions for "Egg tooth"
Keywords:  horny, beak, hatch, pip, protuberance
The temporary horny cap on the duckling's upper bill which serves for pipping (breaking through) the shell. The egg tooth falls off after the duckling hatches.
This is a whitish, horny tubercle near the tip of the upper mandible of a bird embryo. It is used to break the eggshell during hatching, and is cast off shortly after the chick emerges.
A hard pointed knob on the top of the beak of an unhatched peregrine (or other bird) used to break out of the shell.