Britannica Sources used in this answer

How do hatchling turtles and crocodiles break out of their eggs?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A painted turtle (Chrysemys picta) with a dark shell and red and yellow markings rests on a rock near water, surrounded by green aquatic plants. — reptile Painted turtle (*Chrysemys picta*).

To break out of their eggs, hatchling turtles and crocodiles utilize a specialized, pointed structure on their snouts known as a caruncle.12

This caruncle is a horny, keratinous bump rather than a true tooth. The hatchling uses this structure to slice through the amniotic membranes and the inner surface of the eggshell, creating an opening large enough to climb out.132

In the case of crocodiles, the hatching process is often assisted by the mother. As the young begin to chirp and squeak to signal their readiness, the female uncovers the nest and may use her tongue to help the hatchlings emerge from their shells before carrying them to the water. For turtles, hatchlings typically dig upward through the nest material, often in a coordinated effort with other hatchlings, to reach the surface.421