Very Short Answer.
Mention two modifications in Reptiles which are required for terrestrial mode of life.

$\text{Explanation:}$

$\bullet$ The two modifications in Reptiles required for terrestrial mode of life are:

$\text{a)}$ Presence of Amnion: Reptiles are amniotes that is, they have an extra-embryonic membrane called amnion formed during embryonic development. The amniotic fluid inside the amnion prevents the embryo from drying and also acts as a shock absorber. Thus formation of amnion and presence of amniotic fluid led to less dependence on water for development  and allowed amniotes to move to terrestrial habitats.

$\text{b)}$ Cleidoic eggs: The eggs in Reptiles have a hard leathery shell, which protect the embryo and permit retention of water and nutrients inside the egg for the developing embryo.