Reptiles have internal fertilization.

Reptiles, unlike most other animals like amphibians, have internal fertilization. This means that the male's reproductive cells fertilize the female's eggs inside her body. This evolutionary adaptation is crucial for reptiles as it allows for greater protection of the developing embryos, increasing their chances of survival compared to external fertilization. Internal fertilization also enables some reptiles to reproduce on land, away from water bodies, expanding their habitat range and survival opportunities. This unique reproductive strategy has contributed to the success and diversity of reptiles in various environments worldwide.