A. Dinosaurs, along with many other groups of animals, suddenly disappeared from
the planet around 65 million years ago. Why this happened is a question that has
baffled scientists since dinosaur fossils were first discovered. The answer to “why
did the dinosaurs become extinct “is that nobody knows for sure.
There are however a number of theories to account for the mass extinction. Probably
the most popular one is the impact or asteroid theory, proposed in 1980 by American
geologist Alvarez and his team. According to this, a huge asteroid/comet/meteorite
collided with the Earth causing massive amounts of dust and debris to be thrown up
into the atmosphere, blocking out much of the sun and making the Earth too dark and
cold for the dinosaurs to survive. There is evidence suggesting that such an object
crashed into the Yucatan Peninsula in Mexico. A similar yet less popular theory relates
to multiple collisions with the Earth from comet showers.
Some scientists suggest that volcanic activity could have had a role to play in the
extinction of dinosaurs, pumping enough ash into the sky to prevent sunlight reaching
Earth and/or causing massive global warming through the release of ‘greenhouse’ gases.
The Deccan Traps in India (one of the world’s largest volcanic features) are believed
to have been formed through volcanic activity at around the same time the dinosaurs
Another theory is a severe ice age, whilst others have proposed that disease could
have killed off the dinosaurs. And some scientists have suggested that climate change
and lower oxygen levels – to which dinosaurs could not adapt - might have led to
led to their demise.
Perhaps one or a combination of the above theories is correct but, for now, the exact
reason why dinosaurs became extinct remains unanswered.