What Caused the Extinction of Dinosaurs?

Quck answer

The extinction of dinosaurs is believed to have been caused by a combination of factors, including a massive asteroid impact, volcanic activity, and climate change. Around 65 million years ago, a large asteroid struck the Earth, causing a global catastrophe. The impact released a huge amount of energy, triggering massive fires, tsunamis, and a cloud of dust that blocked sunlight for months or even years. This led to a significant drop in temperature and disrupted the food chain, which ultimately resulted in the extinction of dinosaurs and many other species. The surviving animals and plants diversified and evolved, giving rise to the world we know today.

Have you ever watched the movie Jurassic Park? Wouldn’t it be amazing if you could visit a theme park and see real dinosaurs today? Even better, imagine being able to travel to certain parts of the world and witness real dinosaurs still living in the wild?

Unfortunately, none of these scenarios are possible. All the dinosaurs have become extinct. (Although some scientists believe that modern birds evolved from dinosaurs. But that’s a topic for another Wonder of the Day!)

How long ago did the dinosaurs disappear? Experts estimate that it has been approximately 65 million years. This conclusion is based on fossils discovered all around the world. These fossils provide evidence of a mass extinction event that wiped out about 75 percent of Earth’s species!

What could have caused such widespread devastation? This is a question that scientists have been attempting to answer for many years. Today, there are two main hypotheses that they believe might explain what occurred.

The most widely accepted theory is that Earth was struck by a massive asteroid, comet, or meteorite. Scientists have found some evidence to support this theory. They have discovered a layer of the element Iridium, which is uncommon on Earth but abundant in space! Furthermore, the samples they have found date back to approximately 65 million years ago. Is it possible that this layer of Iridium originated from an object that collided with Earth? Many scientists think so.

The layer of Iridium provides strong evidence of an extraterrestrial impact. However, for many years, experts were unable to locate the site where this object struck. Then, in 1991, they discovered the Chicxulub crater. This enormous crater is approximately 110 miles in diameter and is located along the edge of Mexico’s Yucat√°n Peninsula, extending into the Gulf of Mexico.

To form such a crater, scientists believe that the object must have been at least six miles wide and traveling at a speed of about 40,000 miles per hour when it collided with Earth. This impact would have released approximately two million times more energy than the most powerful nuclear bomb.

The heat generated by the impact would have scorched the Earth’s surface, causing widespread fires. Debris launched into the atmosphere would have blocked out the Sun, resulting in a period of darkness. Massive tsunamis would have flooded large areas of the world, while shock waves could have triggered massive earthquakes and volcanic eruptions.

Without sunlight, the Earth would have experienced prolonged darkness, possibly lasting for months or even years. This would have halted the process of photosynthesis and plunged the Earth into a deep freeze. Eventually, greenhouse gases trapped in the atmosphere could have caused a drastic change in climate, leading to the mass extinction.

Of course, the asteroid theory is not the only explanation. Many people believe that volcanic eruptions were responsible for the mass extinction event. This theory points to an increase in volcanic activity in what is now India, which could have had similar effects to an impact event.

According to some scientists, both theories may be accurate and could have occurred simultaneously. It is also possible that an asteroid impact triggered the volcanic activity, amplifying the global effects.

However, testing these theories is impossible and no one would want to cause another mass extinction. Some scientists still hold alternative theories. Until a definitive answer is found, experts will continue to investigate the events that took place 65 million years ago!

Try It Out

If you are interested in learning more about dinosaurs, find a friend or family member to join you in the following fun activities:

  • If you are having trouble visualizing the different periods in which dinosaurs roamed the Earth, don’t worry! There were various types of dinosaurs that lived during different times. Visit the Natural History Museum’s Dino Timeline to gain a clearer understanding of when each dinosaur existed. Based on the information you find, during which period would you have liked to live? Which dinosaur would you have wanted to see in person?
  • Isn’t it fascinating that scientists today can study an impact crater that provides evidence of a meteor, asteroid, or comet causing the extinction of dinosaurs and numerous other species millions of years ago? To learn more, visit the New York Times website and read the article “Digging Into the Chicxulub Crater, Ground Zero of the Dinosaur Extinction.” If you were a scientist studying the crater, what kind of evidence would you seek?
  • You have seen pictures and watched movies and TV shows about dinosaurs, but do you really know what they looked like? Maybe you do, maybe you don’t! Scientists are still analyzing dinosaur bones using new techniques that may provide a better understanding of their appearance. Read National Geographic’s article titled “This May Be Our Best Idea of What a Dinosaur Really Looked Like” to learn more. Afterwards, create your own drawing depicting what you think a dinosaur actually looked like and share it with a friend!

Wonder Sources

  • http://www.history.com/topics/why-did-the-dinosaurs-die-out (accessed 03 Feb. 2020)
  • http://www.nationalgeographic.com/science/prehistoric-world/dinosaur-extinction/ (accessed 03 Feb. 2020)

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