Busy. Please wait.

Forgot Password?

Don't have an account?  Sign up 

show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

By signing up, I agree to StudyStack's Terms of Service and Privacy Policy.

Already a StudyStack user? Log In

Reset Password
Enter the email address associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know (0)
Know (0)
remaining cards (0)
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Dnsr Notes 25

Aliens, Asteroids, and Volcanoes

What percentage of dinosaurs are now extinct? 99.9%
How long did dinosaurs thrive for? 150 my
How many species of dinosaurs exist today? 10,000
How does background extinction compare to mass extinction? Background extinction continually occur and are isolated extinctions. Mass extinctions occur great and small but are still substantial events.
What are the five mass extinctions? End-ordovician, late devonian, end-permian, end-triassic, end-cretaceous
When was the end-Ordovician? (445 Mya)
Late Devonian? (374 mya)
end-permian and what percentage went extinct? (252.5 mya) 80%
end-triassic (201.5 mya)
end-cretaceous (65.5 mya)
What was the K-T extinction? Cretaceous-tertiary
What are the three main hypoth
Created by: Chelseagirl2508