Whats an adaptation that allows reptiles to survive farther from water than amphibians?

Despite their vulnerability to dessication, amphibians have managed to survive in desert areas, far away from any permanent sources of water. They do this mainly be avoiding the high temperatures of day time, emerging only at night, and by seeking refuge below ground surface. Nevertheless, many amphibians still have to rely on the availability of bodies of water to reproduce. Reptiles, by evolving the shelled egg, are able to reproduce without any bodies of water. Even though reptilian eggs are also somewhat vulnerable to dessication, the lack of a free swimming larval stage allows the eggs to develop on land.