The reptile clade includes five,extant groups: tuataras,snakes and lizards,turtles,crocodilians,and birds.When you compare current textbooks with older textbooks,you notice that in older textbooks,birds were not included with reptiles. -Based on current research data on birds and reptiles,what would be the most obvious reason(s)for the earlier classification?
A)Birds are endotherms and the other lineages are ectotherms. B)Birds had feathers and could fly. C)Birds have no teeth and smaller skulls. D)Birds' eggs are very different from reptilian eggs. E)Both A and B are correct.