Question

you have replied that birds are classified as birds because they lay eggs but what about reptiles? even they lay eggs but they are not birds so what is the correct classification of birds ? feathers or eggs

Answer 1

All reptiles are oviparous means they lay eggs that hatch into young ones. But actually that is not entirely true. Some exceptions are there. Some snakes like Boa snakes, Garter snakes and most of the Viper snakes are ovoviviparous that means they retain the eggs within their body and the babies hatch inside the mother and come out later on. So, they also lay eggs but have some modification in terms of giving birth to young ones and all reptiles are oviparous. So feathers are the basis of classification of birds.