Here's a breakdown:
* Dinosaurs: Belong to the Dinosauria clade, a group of reptiles that existed for over 180 million years and went extinct about 66 million years ago.
* Bears: Belong to the Carnivora order, a group of mammals that includes all the meat-eating mammals, including dogs, cats, seals, and weasels.
In simpler terms, dinosaurs are ancient reptiles, and bears are modern mammals.