Question

The extinction of which group of animals 65.5 million years ago is thought to have been due to an impact event and global climate change?

Answer 1

The Mesozoic Era the age of dinosaurs is thought to have ended about 65.5 million years ago

Explanation:

A fossil strata containing dinosaurs are believed to be at least 65 million years old.

The most popular theory is that a comet or astroid struck the earth creating a dust cloud that changed the climate of the earth. The dinosaurs being ( at least mainly) cold blooded were not able to adapt to the rapid change in climate.

The early theory of Continental Drift, attributed the climate change to the rapid movement of the continents ( plates due to the modern theory of plate tectonics) causing increased volcanic activity creating dust clouds, that caused the climate change.

Another theory is that there was a disease that attacked the dinosaurs which swept across the world causing the dinosaurs to become extinct.