The dinosaurs became extinct around 65 million years ago, at the end of the Cretaceous period.
Although the dinosaurs were the largest of the creatures to become extinct at this time, they weren’t the only creatures to disappear - lots of smaller species also died out during this time period, too!
Over the years, there's been a lot of debate as to what actually killed the dinosaurs. The asteroid theory has the most evidence behind it, though, and scientists are pretty confident that it's right. Unfortunately, the T-Rex had very short, useless arms - I'm sure he'd have left us a diary otherwise!
The Asteroid Theory
65 million years ago, an asteroid with a diameter of 110 meters hit Earth - there's a huge crater under Mexico to prove it!
Scientists believe that the collision threw loads of dust into the air, and this blocked the sun's rays. Due to lack of exposure to sunlight, many animals and plants died.
The collision also brought dramatic changes in climate, and it all became too hot and then too cold for the poor dinosaurs. Soon, they began to die (that's if the meteor hadn't already landed on them) and extinction followed.
Volcanic Activity
A large increase in volcanic activity may have spewed lots of debris into the air, and this would have blocked out the sun and caused the death of the dinosaurs.
Ice Age Theory Theoretically, a severe ice age could also have caused the dinosaurs' extinction. The severe ice would have caused temperatures to plummet and frozen all the water. The dinosaurs wouldn't have been able to survive under such conditions - they'd get thirsty!
Disease There are also theories that a contagious and deadly disease may have killed the dinosaurs, and as humans didn't live back then, there was nobody to take them to the vet.
Regardless of which theory is the correct one, it is generally accepted that the dinosaurs disappeared around 65 million years ago. This has been determined through the studying of sedimentary rocks and fossils, as well as DNA evidence.
Although the dinosaurs were the largest of the creatures to become extinct at this time, they weren’t the only creatures to disappear - lots of smaller species also died out during this time period, too!
Over the years, there's been a lot of debate as to what actually killed the dinosaurs. The asteroid theory has the most evidence behind it, though, and scientists are pretty confident that it's right. Unfortunately, the T-Rex had very short, useless arms - I'm sure he'd have left us a diary otherwise!
The Asteroid Theory
65 million years ago, an asteroid with a diameter of 110 meters hit Earth - there's a huge crater under Mexico to prove it!
Scientists believe that the collision threw loads of dust into the air, and this blocked the sun's rays. Due to lack of exposure to sunlight, many animals and plants died.
The collision also brought dramatic changes in climate, and it all became too hot and then too cold for the poor dinosaurs. Soon, they began to die (that's if the meteor hadn't already landed on them) and extinction followed.
Volcanic Activity
A large increase in volcanic activity may have spewed lots of debris into the air, and this would have blocked out the sun and caused the death of the dinosaurs.
Ice Age Theory Theoretically, a severe ice age could also have caused the dinosaurs' extinction. The severe ice would have caused temperatures to plummet and frozen all the water. The dinosaurs wouldn't have been able to survive under such conditions - they'd get thirsty!
Disease There are also theories that a contagious and deadly disease may have killed the dinosaurs, and as humans didn't live back then, there was nobody to take them to the vet.
Regardless of which theory is the correct one, it is generally accepted that the dinosaurs disappeared around 65 million years ago. This has been determined through the studying of sedimentary rocks and fossils, as well as DNA evidence.