Do Amniotes Lay Eggs?

Amniotes are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals. Amniotes are characterized by having an egg equipped with an amnion, an adaptation to lay eggs on land or retain the fertilized egg within the mother.

Do all amniotes lay eggs?

Because reptiles, birds, and mammals all have amniotic eggs, they are called amniotes. The duck-billed platypus and some other mammals also lay eggs. But most mammals have evolved amniotic eggs that develop inside the mother's womb, or uterus, and so lack a shell.

Do amniotes lay eggs in water?

They are distinguished by a membrane (amnion) protecting the embryo and a lack of a larval stage. Thanks to this, amniotes lay eggs on land or retain them within the mother, unlike anamniotes (fishes and amphibians), which typically lay eggs in water.