Flaky skin of reptiles prevents them from the harsh environment of the earth. It is speculated that reptiles transitioned from amphibians some 50 million years ago, which perhaps explains why there are so many commonly shared characteristics. Reptile is the group of animals that live on land, have a scaly skin, breathe through lungs and lay eggs. Seymouria is the organism known for the link, as it has skull properties like amphibians and skeleton of reptiles. Amphibians are also said to be the link between the fish and the terrestrial reptiles, the first animals who migrate from sea to land. The fundamental difference between amphibians and reptiles lies in their life cycle and physical appearance. At one time, reptiles and amphibians were zoologically classified as reptiles due to their many similarities. Main Difference. Let's first identify those similarities between reptiles and amphibians. Amphibians and Reptiles are two basics classed of living organisms. Most of the time people mixed the organism belonging from these two different classes due to their basic similarity and which is that both these classes possess cold-blooded animals.