Differences between reptiles and amphibians Feature The integument (skin): structure; waterproofing Comparison between amphibians and reptiles Amphibians: Reptiles: Circulation: Structure of the heart Amphibians: Reptiles: Reproduction: How eggs are fertilized; Where / how young incubate / gestate Amphibians: Jaws and teeth Amphibians: Reptiles: Reptiles: Respiration: Respiratory surfaces; how the lungs are ventilated Amphibians: Reptiles: Orientation of the limbs (relative to the body) Amphibians: Reptiles: