The possession of scales, laying of eggs with shells and bony structure of the head are characteristics shared by
birds and reptiles
fishes and birds
reptiles and fishes
birds and molluscs
Correct answer is A
Its long been recognized that birds and reptiles share many characteristics:
Both have skulls that abut the first neck vertebra with a single ball-and-socket joint.
Both birds and reptiles excrete nitrogenous wastes as uric acid; mammals excrete urea, fish ammonia.
Both lay similar highly yolked eggs
Bird feather is homologous to the reptile scale. Both develop from an epidermal elevation over a nourishing dermal core. Scales flatten, feather buds roll into a cylinder shaped tube.