Question

Name and motivate the most important evolutionary step which distinguishes reptiles from amphibians.

Answer 1

The reptiles are distinguished from amphibians by their terrestrially adapted egg, which is supported by four extraembryonic membranes :the yolk sac, the amnion, the chorion and the allantois.

Also amphibians can breathe underwater with gills and on land with lungs, reptiles can only breathe on land with lungs.