How did the dinosoures die?

Nobody really knows for sure, but here are some theories.

According to the Asteroid Impact Theory, a large asteroid or comet collided with Earth about 65 million years ago. Scientists found a layer of iridium, worldwide, to explain this theory.

Another theory that could explain how the dinosaurs became extinct is volcanic activity. A huge increase in volcanic activity at around 65 millions years ago (possibly started by that asteroid impact) could have blown so much ash into the air that it would have blocked out the sun, killing off the dinosaurs.

Some scientists believe that there was a severe ice age. Throughout Earth's history there have been many ice ages. The last one ended about 10,000 years ago. A very severe ice age could have changed temperatures and frozen a lot of Earth's water. The dinosaurs would not be able live under such conditions and that is how the dinosaurs became extinct.

It has also been suggested that disease killed off the dinosaurs. A very deadly and contagious desease may have circulated among the dinosaurs forcing them to become extinct.Still yet another theory is that the Earth just gradually changed in climate over a long time period and the dinosaurs were not able to adapt to the cooler, dryer climate.

There are probably other theories as to how the dinosaurs became extinct.