An organism that lays eggs that can be incubated in air (externally) because the embryo is enclosed by a fluid-filled sac. Birds and reptiles are amniotes.
A tetrapod that lays shelled eggs, such as reptiles and birds.
An animal that produces an embryo within a sac that contains amniotic fluid. Amniotes include turtles, lizards, snakes, tuataras, crocodilians, birds, and mammals.
Amniotes are animals whose eggs contain an amnion, a membrane that surrounds the embryo and helps retain fluids. Mammals (including whales), birds, dinosaurs, turtles, and lizards are amniotes.
A species of animal which possesses an amnion. This term is most often used in the plural (amniotes) to refer to reptiles, birds, and mammals collectively.
The amniotes are a taxon of tetrapod vertebrates that include the Synapsida (mammals and mammal-like reptiles) and Sauropsida (reptiles and dinosaurs, including birds). They are defined by embryonic development that includes the formation of several extensive membranes, the amnion, chorion, and allantois. Amniotes develop directly into a (typically) terrestrial form with limbs and a thick stratified epithelium, rather than first entering a feeding larval tadpole stage followed by metamorphosis as in amphibians.