The most populaur one is that the weather became cooler, and the dinosaurs had no feathers or fur to protect them against the changing weather. Others are like a star exploded, but then how could some other speacies have lived. Another one is that an astioriod hit the earth and made the land dark for three, or so , years. So only the animals that could live on nuts or rotten plants could live. They also think that they have the rock.
Dinosaurs are very interesting in many ways.
I hoped you liked the report.