The sky is falling

6 theories that explain why dinosaurs really went extinct

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Even if you weren’t paying attention in science class, you probably know that an asteroid (known to scientists at the Chicxulub impactor) killed the dinosaurs.

It’s a fact that even kids’ cartoons and bizarre ‘90s sitcoms assume everyone knows — so why is this 66-million-year-old case still open?

As it turns out, the space rock may not have acted alone. Here are 6 recent findings on what really killed the dinosaurs.

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6.

Researchers from Harvard University theorize that a comet captured by Jupiter’s gravity, not an asteroid, killed the dinosaurs.

They say the comet could have broken into pieces as it slingshotted through the Sun’s gravitational pull and one of these pieces struck the Earth.

The Chicxulub crater contains material that may support this theory, as it’s found more in comets from the Oort Cloud than objects from the Asteroid Belt.

University of Texas at Austin

5.

Researchers from the University of Texas at Austin say iridium-containing asteroid dust at the Chicxulub crater proves that an asteroid was the culprit.

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Rare in the Earth’s crust, iridium is common in asteroids and it began showing up in greater quantities in the geological record around the time of the theorized asteroid’s impact.

4.

Scientists from the U.S. and India say earthquakes caused by the Chicxulub impactor let magma flow more freely from the Earth’s crust.

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That could have intensified volcanic eruptions in a lava-covered area of the Indian subcontinent called the Deccan Traps for up to 500,000 years, keeping ecosystems from recovering.

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3.

The Chicxulub impact could have created shockwaves strong enough to separate tectonic plates on the ocean’s floor and release the magma beneath, researchers from the Universities of Oregon and Minnesota say.

Methane and other gases released by these underwater eruptions would have further disrupted ecosystems for creatures that survived the initial impact.

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2.

Researchers from the U.K. and the U.S. say the Chicxulub impact may have spared the dinosaurs if it struck moments sooner or later, landing in the deep ocean.

That would have caused less vaporized rock to enter the atmosphere and blunted the nuclear winter effect that killed much of the life on Earth.

1.

Scientists think dinosaurs were in decline millions of years before dying out, and researchers from the University of Albany say it may be because of their diet.

They argue that dinosaurs lacked taste aversion, which keeps animals from eating food that once made them sick, and thus fed on toxic plants.

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Crocodilians, which have evolved relatively little in recent history and share an ancestor with dinosaurs, also lack taste aversion, which could lend credence to the theory.

Read more stories on animals here.

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