What Killed the Dinosaurs?

18 Jul , 2013 by Video

Dinosaurs roamed the Earth for 135 million years. Filling every ecological niche, from the oceans, forests and plains; even the skies.

Then, 66 million years ago, something terrible happened. In a geological instant, 75% of the plants and animals on Earth went extinct. And all of the land dinosaurs were wiped off the Earth forever.

What happened? What killed them off?

What could have caused that much damage in such a short amount of time?

The key to this mystery was found in a strange layer of ash sandwiched between layers of rock deposited 66 million years ago. This line, known as the Cretaceous-Paleogene boundary, is found across the world in the geologic record and it marks the moment when everything DIED. What’s interesting about this layer is that it’s rich in iridium, a rare element on Earth, but abundant in asteroids.

And so, geologists found the most likely culprit: an asteroid.

This evidence matched the discovery of an enormous asteroid impact basin in the Yucatán Peninsula in Mexico, centered near the town of Chicxulub. The rock debris in this area could be dated back to approximately 66 million years old, matching the worldwide layer of ash.

We now know that an asteroid at least ten kilometres across slammed off the coast of Mexico 66 million years ago, releasing 2 million times more energy than the most powerful nuclear bomb ever detonated.

The effect of this impact is mindblowing.

Chicxulub Crater

Chicxulub Crater

Millions of tonnes of rock were ejected into space on ballistic trajectories. Reheated by atmospheric re-entry, this debris superheated the air across the entire planet, catching the world’s forests on fire.

Shockwaves radiated outward from the impact site, inducing earthquakes and volcanoes along their path. Mega tsunamis thousands of meters high spread out from the impact site, pounding coastlines around the world.

Dust rained down across the planet. It filled the air, darkening the skies for decades, and preventing photosynthesis. Plants on land and in the oceans were unable to produce energy.

The planet cooled from the choking dust and aerosols, followed by years of acid rain, and then even global warming as the carbon from the blasted life filled the atmosphere.

Artists concept of asteroid impact event

Artists concept of asteroid impact event

The effects to life were devastating.

It’s no surprise the land dinosaurs didn’t make it through this impact event. In fact, it’s a bigger surprise that our ancient ancestors, hardy early mammals could endure.

And our final sobering thought is that impacts of this scale have happened many times in the past, and will happen again in the future.

It’s not a question of if, it’s a matter of when.

Additional Reading:
Scientists Come to a Conclusion: An Asteroid Killed the Dinosaurs
Giant Impact Near India Might Have Killed the Dinosaurs
Were the Dinosaurs really wiped out by an asteroid? Maybe not


Sort by:   newest | oldest | most voted
Kevin
Member
Kevin
July 18, 2013 6:25 PM

According to my Dinosaurs Attack cards, we did!

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
July 18, 2013 7:03 PM
And our final sobering thought is that impacts of this scale have happened many times in the past, and will happen again in the future. Sigh. Not this again. That observation alone rejects impactors as high extinction risks, because only one mass extinction has ever been conclusively shown to be triggered by an impactor. Further back larger impactors happened without any observable blips, and the risk for impactors goes down exponentially over time. The resolution is the same that was presented in the latest review and have AFAIK stayed since then. This specific impact happened to hit calciferous and sulfurous sediments that were scare before and are relatively scarce still. Impact will happen, but mass extinctions from impacts… Read more »
universetoday
Member
July 18, 2013 7:31 PM

I’m glad to take such a ribbing from a 7-year old dinosaur fan. I think I can probably dig up a few.

meekGee
Member
meekGee
July 18, 2013 10:40 PM
Torbjorn – there’s one major consideration you’re overlooking. Pre-civilization, the environmental change caused by the impactor had to physically kill the animals. A much smaller impact, one that merely caused 10 years worth of bad winters, would simply have caused some small effect on the populations. In our modern world, there’s a very fragile system in place that supports the 6 (7? 8?) Billions of us. If, for example, because of bad weather, we lose electric power on a global scale for more than a week, then there’s no water, no fuel, no food – and likely a huge amount of death. There are millions of people in every major city, that without infrastructure are simply doomed. And… Read more »
IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
July 19, 2013 3:09 AM

What Killed the Dinosaurs?

Dinosaur farts! Seriously!

Aqua4U
Member
July 19, 2013 6:08 AM

HOOT! That’s a gas!

Coacervate
Guest
Coacervate
July 19, 2013 4:59 AM

“The term “dinosaur” is restricted to just those reptiles

When are you going to learn that the term dinosaur is not restricted to reptiles because they are not reptiles. Shape up slacker

PrometheusOnTheLoose
Member
July 19, 2013 12:05 AM

If mankind gets off its behind and creates a good enough detection system, these things can be spotted long before they are anywhere near the earth . . . . and the sooner the force is applied to re-route them, the greater the re-routing effect will be. If mankind does nothing and waits, then we will join the dinosaurs . . . . and perhaps have our bones dug up some day.

Aqua4U
Member
July 19, 2013 5:41 AM
As a child I had recurring nightmares about a Tyrannosaurus Rex chasing me! (Gorgo?) I’d hide under cars then scramble out from under it at the last possible second as the dinosaur looked under and saw me. These dreams always woke me up and I’d be in a cold sweat – MA MAAA! LOL! Turns out, this is a classic childhood nightmare..Did you experience similar? Today, with the magic of CGI, Jurassic Park and other fantasy movies have brought those creatures to life for almost every child. I’ll bet there are a few out there who’ve had similar ‘bad dreams’? Thanks Holywad… I think? SciFi short story subject: 66 million years ago, an overpopulated and expanding space faring… Read more »
Joshua Dean
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Joshua Dean
July 19, 2013 4:16 PM

WTFDIJR?

William928
Member
William928
July 19, 2013 9:29 PM

I’d like a bit of what Aqua4U is smoking……..

Matt McDowall
Guest
Matt McDowall
July 19, 2013 4:20 PM

I thought the dinosaurs just didn’t make it to the ark in time…and that’s why they all died, they drowned ;-P

MikeF318
Member
MikeF318
July 19, 2013 6:54 PM
There is actually quite a bit of evidence that most, if not all, of the species of dinosuar that went extinct 65 million years ago, were already extinct at the time of this impact. Massive volcanic eruptions took place over a million years or so (IIRC) either in Siberia or in India. The continued eruption I am trying to remember was in one of those two locations, as it pertains to this issue, although massive eruptions did take place in both locations at some point. I think it is the Siberian Traps (?) that are relevant to this issue as the Indian eruptions were caused by the sub-continent of India breaking apart from Africa and moving north to… Read more »
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