You are presented with the quiz "what have evolved from reptile scales of bipedal dinosaurs called theropods" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "birds evolved from a group of bipedal dinosaurs called theropods" and "bird's feathers have evolved from reptile scales". 

So, what's the best answer to the question?


 

   feathers        