Birds and reptiles are both vertebrates that lay eggs but birds have beaks and reptiles have teeth. Occasionally birds have teeth but only in the embryonic stage. Which conclusion is best supported by the presence of teeth in bird embryos?
A. Ancestors of reptiles had beaks similar to those of birds.
B. Birds and reptiles eat similar types of food.
C. Birds and reptiles share a common ancestor.
D. Modern reptiles are the ancestors of modern birds.

Question

Birds and reptiles are both vertebrates that lay eggs but birds have beaks and reptiles have teeth. Occasionally birds have teeth but only in the embryonic stage. Which conclusion is best supported by the presence of teeth in bird embryos?
	A.	Ancestors of reptiles had beaks similar to those of birds.
	B.	Birds and reptiles eat similar types of food.
	C.	Birds and reptiles share a common ancestor.
	D.	Modern reptiles are the ancestors of modern birds.

anonymous · Answer

According to my zoology notes from last semester, this is (more or less) how the taxa are related: |dw:1340142254204:dw|