All birds lay amniotic eggs with hard shells made mostly of calcium carbonate.

The beaks of many baby birds have a projection called an egg tooth, which facilitates their exit from the amniotic egg.

The above example, concluding that Tyrannosaurus could lay amniotic eggs, is the standard type, and is called a type I inference.

The chorion is one of the four extraembryonic membranes that make up the amniotic egg that provide for the nutrients and protection needed for the embryo's survival.

In 1866, Haeckel demonstrated that vertebrates could be divided based on their reproductive strategies, and that reptiles, birds, and mammals were united by the amniotic egg.

Most reptiles lay amniotic eggs covered with leathery or calcareous shells.

The female lays amniotic eggs in which the young fetus continues to develop after it leaves the female's body.

Amniota (amniotic eggs)

The cleidoic egg is sometimes called the amniotic egg, because it is characteristic of amniotes.

They obtain oxygen though lungs instead of gills from birth and lay amniotic eggs, which consists of a hard shell.