noun
- a vertebrate animal whose embryo is enclosed in an amnion, including mammals, birds, and reptiles
Usage: biology term; contrasts with anamniotes (fish and amphibians)
Examples
- Humans are amniotes because our embryos develop within an amniotic sac.
- Birds and reptiles are amniotes that lay eggs with protective membranes.
- The evolution of the amnion allowed amniotes to reproduce on land without returning to water.
- Unlike fish, all amniotes have an amnion surrounding the developing embryo.
- Mammals, birds, and reptiles are the three main groups of amniotes.