Extant nonbird reptiles are ectothermic whereas birds are different in that they are endothermic. Extant nonbird reptiles are scaly and amniotes whereas birds are different in that they are lacking in scales amniotes.
Step-by-step explanation:
Amniotes are the characteristics of extant reptiles and birds in which they lay eggs on land.
Extant non bird reptiles are different from amphibians, and they have following characteristics:
Amniotic eggs : Reptiles lay down hard shelled eggs.
Presence of scale or integument: The scales on the reptile skin help it to adapt land environment and provide protection by preventing the water loss by skin.
ectothermal or cold-blooded : these cannot control their body temperature on their own.
Require less food than birds and mammals and can best survive in deserts.
Bird or Aves characteristics:
The presence of wings and feathers.
Endothermic: They are capable of changing their body temperature according to the environment.
Ovoparous:All birds lay eggs.
Amniotes: The eggs of the bird is protected by amniotic layers.