Final answer:
The amniotic egg contributed to early reptile success by providing protection with its hard leathery exterior and ensuring a water-tight environment for embryo development. Containing yolk for nourishment, it allowed reptiles to thrive in various terrestrial habitats and reduced dependency on water for reproductive processes.
Step-by-step explanation:
The amniotic egg represented a fundamental advancement for early reptile survival on land. One advantage of this type of egg is the protection provided by its hard leathery exterior or hard calcium covering, which safeguards the embryo from environmental hazards and potential predators.
Another key advantage is that the amniotic egg is water-tight, eliminating the need for a constantly moist environment and protecting the developing fetus from dehydration.
This allowed reptiles to lay their eggs in a variety of terrestrial environments. Additionally, the amniotic egg contains yolk as a source of nourishment for the embryo, supporting its development without the dependence on an external aquatic environment.
Furthermore, the evolution of other physical traits such as scales containing keratin, the paired with the adaptation of amniotic eggs, enabled reptiles to colonize drier habitats and reduce their dependency on water bodies for reproduction and development, thus distinguishing them from amphibians whose eggs required moist conditions.