On the basis of what data are amphibians considered the ancestors of reptiles?

Reptiles evolved from amphibians through a long evolutionary process. This is evidenced by a lot of evidence. First of all, there are similar morphological features. Also, they have similar organ systems. We see that the heart of amphibians, like the heart of reptiles, consists of three chambers. Also, they have two circles of blood circulation. Fish have only one circle of blood circulation and a two-chambered heart. Also, both amphibians and reptiles are cold-blooded animals, that is, they are not able to maintain a constant body temperature.