Dinosaurs Extinction : Reasons and Theories

The dinosaurs were the great ruler of the earth before human life was even born. They were mighty,fierce,ferocious animals. The last dinosaurs died approximately 65 million years ago. Why did they become extinct? Although the cause of their extinction is still a mystery, climatic change, diseases, changing plant communities, and geologic events could all have played a role.
image

The theories of dinosaurs becoming extinct are subject of much debate and controversy. A recent explanation, supported by many scientists, suggests that dinosaurs died out soon after a huge meteorite crashed to Earth near the Gulf of Mexico. A giant meteorite, they reason, could have landed with an impact that kicked up enough dust and debris to block out sunlight for a long time — leading to a deadly chain of events. Without the sun, all the plants died; without the plants, all the plant-eaters died; and without the plant-eaters, all the meat-eaters died. Sounds reasonable. But there is one problem with this theory: Paleontologists have not yet been able to find dinosaur skeletons in rocks dating to the period of impact. Some evidence even seems to indicate that all the dinosaurs had died before the meteorite hit.

What is the answer? As paleontologists search for clues to support their theories, they agree to disagree.

Where Did All The Dinos Go? Some Leading Theories

(1) A big meteorite crashed into Earth, changing the climatic conditions so dramatically that dinosaurs could not survive.

(2) Ash and gas spewing from volcanoes suffocated many of the dinosaurs.

(3) Diseases wiped out entire populations of dinosaurs.

(4) Food chain imbalances lead to the starvation of the dinosaurs.

 

Adapted from Dinosaurs: The Very Latest Information and Hands-On Activities From the Museum of the Rockies, by Liza Charlesworth and Bonnie Sachatello-Sawyer; a Scholastic Professional Book.

Advertisements

মন্তব্য করুন

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / পরিবর্তন )

Twitter picture

You are commenting using your Twitter account. Log Out / পরিবর্তন )

Facebook photo

You are commenting using your Facebook account. Log Out / পরিবর্তন )

Google+ photo

You are commenting using your Google+ account. Log Out / পরিবর্তন )

Connecting to %s