How did dinosaurs become extinct?

Dinosaurs ,that everyone is now aware of, were the dominant vertebrate animals of the terrestrial ecosystems for over 160 million years, first appearing approximately 230 million years ago.

What happened to them?
Why they became extinct? Whats the reason?

The answr to one of the most enduring scientific mysteries could be buried deep inside the earth & efforts r underway to literally get to the bottom of the mystery.

Some believe tha mass emission of poisonous gases due to big volcanic eruptions in south India over 65 million years ago was responsible for their deaths.

Some also believe that at the end of the Cretaceous Period, 65 million years ago, a catastrophic extinction event ended the dominance of dinosaurs on land.