Answer the following question given this paragraph: 

Cynodonts probably gave rise to mammals about 200 million years ago. However, they are not considered to be mammals themselves. In fact, competition with early mammals may have led to their extinction. They went extinct sometime during the Jurassic or Cretaceous Period.


Q: Competition with what emerging animal group may have led to extinction of cynodonts about 200 million years ago?


A:
mammals