changes in the environment diseases causing illness changes in the weather predator animals
I gave my students this multiple choice question: The ichthyornis was a type of bird that lived over 65 million years ago. It lived near the sea and hunted for fish over the water. Fossils have been found in Kansas, many miles from the present-day ocean. Which cause of extinction is most likely to be found in the fossil record along with ichthyornis fossils?

Only one answer is correct among these 4 choices:
- changes in the environment
- diseases causing illness
- changes in the weather
- predator animals

Could you tell me which one is correct?

changes in the environment