Answer:
The answer is below
Step-by-step explanation:
65 million years ago, a mass extinction occurred which wiped out about 50% of all living things on earth. This led to the end of Cretaceous period and the beginning of the Tertiary period. This mass extinction led to the extinction of all dinosaur species on earth. The tertiary period lasted from approximately 66 million to 2.6 million years ago. The mass extinction was as a result of climate and geological changes.