Final answer:
Both the Permian and Cretaceous Periods ended with massive extinction events, with the latter marked by the extinction of the dinosaurs.
Step-by-step explanation:
The Permian and Cretaceous Periods have in common that both periods were characterized by a mass extinction event. The end of the Permian period saw the largest mass extinction event in Earth's history, eliminating an estimated 95 percent of extant species. Similarly, the end of the Cretaceous period was marked by another mass extinction event, approximately 65 million years ago, which is famous for causing the demise of the dinosaurs and many other species following a large meteor impact.