Is external fertilization possible in animals whose eggs have a hard shell (lizard, snake, turtle, birds)? Why?

In this case, external fertilization is impossible. All because of the hard shell of the egg. It does not allow male reproductive cells to penetrate there. These animals are more developed than fish and amphibians, therefore they have internal fertilization. An embryo is formed in the egg. Since its development takes place outside the mother’s body, it needs good protection from environmental factors. This is what the shell is for. Most fish and amphibians lay eggs, which the male fertilizes. This is possible due to the lack of a strong shell.