But now it has been suggested they were sent into eternity by an equally catastrophic but somewhat smaller threat - biting insects.

Disease spread by mosquitoes, mites and ticks was probably the major factor that finished off the reptiles, say scientists.

The insects could have also made it harder for dinosaurs to survive by changing the nature of plant life.

Bees and other pollinators helped promote the rapid spread of flowering plants, leading to the loss of vegetarian dinosaurs' traditional food sources. As the planteating dinosaurs declined, so would their predators.

The theory helps explain why dinosaurs took so long to die off, say husband-and - wife team George and Roberta Poinar.

According to the most widely accepted explanation, the dinosaurs vanished after an asteroid or comet hit the Earth between the Cretaceous and Tertiary periods.

Another theory is that they were driven to extinction by massive volcanic eruptions in India, which led to extreme climate change.

 Source : Daily Mail UK