Reptilian jaws are efficiently designed for applying crushing or gripping force to prey. Reptiles have some form of copulatory organ permitting internal fertilization.
Reptiles have a more efficient circulatory system and higher blood pressures than amphibians.
Reptile lungs are better developed than those of amphibians. Reptiles have evolved efficient strategies for water conservation. All reptiles, except the limbless members, have better body support than the amphibians and more efficiently designed limbs for travel on land. The reptilian nervous system is considerably more advanced than that of the amphibian. Hickman, C.P. and L.S. Roberts.