We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Caused the Dinosaurs to Go Extinct?

Michael Anissimov
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

All dinosaurs, except a few which would later go on to become modern birds, went extinct about 65.5 million years ago, during the Cretaceous-Tertiary extinction event. No land animal larger than a cat survived. The sky was largely blacked out for a period of years to decades, killing numerous plant and microbe species which rely on photosynthesis to survive. Species that depended on the consumption of plant matter, such as all vegetarian dinosaurs, went extinct when their food sources died off and decomposed. In North America alone, 57% of plant species went extinct. In paleontology, the layer of rock that corresponds to this extinction is known as the K-T boundary.

Even today, we don't know with 100% confidence what really caused this massive extinction. But the prevailing theory, by Nobel Prize-winning physicist Luis Alvarez, is that a 6-mile asteroid impacted the Earth, releasing the energy of 2 million atomic bombs and raining molten magma across the entire surface of the planet.

Alvarez's extinction theory is supported by two facts: first, the huge Chicxulub crater on the Yucatan peninsula in Mexico can be dated to the time of the K-T boundary. Second, all across the world, the K-T boundary rock contains an unusually high proportion of iridium, a substance very rare of the Earth's surface, but more plentiful in asteroids. This suggested that the debris from the impact fell everywhere on the globe. This illustrates the destructiveness of the impact. The rock underneath the crater is rich in gypsum, which would have produced clouds of sulfur dioxide aerosol in the aftermath of the collision, resulting in acid rain and killing marine creatures that depend on their shells for survival.

Being very large and exposed on the surface, as well as more highly dependent on smooth ecosystems than less specialized plants and microorganisms, dinosaurs were hit with the brunt of the extinction effects. The Chicxulub asteroid slammed into the Earth at an angle, traveling northwest. This would have thrown magma-hot, ballistically reentering ejecta all across what is today the central United States, an area known for its large dinosaur populations.

The direct effects of the heat could have killed off 99% or more of the dinosaurs within hours. Those who were able to survive the rain of magma would die over the next years or decades, their food sources drying up, and ecosystems becoming completely unraveled. Life would never be the same again: from that point on, it was not the dinosaurs, but smaller warm-blooded animals that would thrive on planet Earth.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology, astronomy, chemistry, and futurism to his articles. An avid blogger, Michael is deeply passionate about stem cell research, regenerative medicine, and life extension therapies. His professional experience includes work with the Methuselah Foundation, Singularity Institute for Artificial Intelligence, and Lifeboat Foundation, further showcasing his commitment to scientific advancement.
Discussion Comments
By anon251257 — On Feb 29, 2012

It's a basic concept of 2012 by now. Back in 1990, this would be helpful but now in 2012, this is basic preschool common sense.

By anon110847 — On Sep 13, 2010

This info is useful but i need help writing a report.

By anon87481 — On May 30, 2010

i found this article particularly helpful due to the fact that i have a very important assignment based on the extinction of the dinosaur.

Michael Anissimov
Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology...
Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.