EVERYDAY SCIENCE

Detailed explanation-1: -Reptiles were the first amniotic vertebrates. Mammals and birds, which both descended from reptile-like ancestors, evolved endothermy, or the ability to regulate body temperature from the inside.

Detailed explanation-2: -Reptiles. Reptiles were the first amniotes and the first organisms to develop internal fertilization.

Detailed explanation-3: -Birds, reptiles, and mammals have amniotic eggs. Because amphibian eggs don’t have an amnion, the eggs would dry out if they were laid on the land, so amphibians lay their eggs in water.

Detailed explanation-4: -Unlike amphibians, reptiles produce amniotic eggs (see Figure below). The shell, membranes, and other structures of an amniotic egg protect and nourish the embryo. They keep the embryo moist and safe while it grows and develops.

Detailed explanation-5: -Reptiles were the first vertebrates that possess amniotic eggs. Amniotic eggs have extraembroynic membranes.