I believe it will be amniotic eggs. birds have hollow bones but reptiles don't. and birds are endothermic rather than ectothermic. birds don't have scales and reptiles don't have beaks or feathers obviously. and they both do have amniotic eggs.
Presence of scales and ectothermic are the features of reptiles. Presence of beaks, feathers and hollow bones are the features of birds. Whereas both reptiles and bird have amniotic eggs. Amniotic eggs are those in which developing embryo is surrounded by a membrane called amnion. Inside amnion, amniotic fluid is filled, which protects the developing embryo from external shock. Amnion containing eggs are called amniotic eggs.
