One reproductive adaptation that oviparous reptiles and birds survive the harsher conditions on land was the

Amniotic eggs.

Explanation:

Amniotic eggs are the eggs produced by the birds, reptiles and mammals. The embryo develops inside the amniotic egg. The shell of the egg is made of hard calcium elements.

The main function of the amniotic egg is to protect the embryo from the harsh dry conditions. The development of amniotic egg is the type of reproductive adaptation that are used for the protection of their embryo. The eggs can survive on the conditions of the land environment.

Thus, the answer is amniotic egg.

yes? sounds right, but you didn’t ask a question.