Why are dino's extinct

No one nows the exact reason for why the dinosaurs have dissapeared since there was no human life to wittness the event. The theories are varied. The most popular thoery is the Asteriod theory. A massive asterioad hit the world 65 million years ago. If the asteriod landed on land, the impact would have started up dust storms that would cover the earth. Because the dust seals the sun's rays from earth, the earth freezes, but before that the plants would die out because of lack of sunlight, and the animals that lived on the plants would start to die out. That leads to the deaths of the animals that depended on the meat of the plant eating animals which made the entire dinosaur race die out. There is a theory that dinosaurs became extinct as a result of volcanic activity. There was an impact on the core that started off millions of volcanos, a lot of dinosaures would have died in the volcanic explosion but the result of the deaths of the dinosaur race would be the ash pumped into the atmospher which would have blocked the sun's rays from earth, the earth freezes, but before that the plants would die out because of lack of sunlight, and the animals that lived on the plants would start to die out. That leads to the deaths of the animals that depended on the meat of the plant eating animals which made the entire dinosaur race die out.Some scientists believe that there has been a server iceage which has been effecting earth for 10000 years have wiped out the dinosaurs.
But there are other theories on how dinosaurs have been extinct alien attacks, easrthquakes, tornadoes and there are loads of other theorys.