K-T boundary
nounDefinition of K-T boundary
: the transition between the Cretaceous and Tertiary periods of geologic time characterized by a mass extinction of many forms of life including the dinosaurs also : a geologic stratum marking this boundary
Keep scrolling for more
Comments on K-T boundary
What made you want to look up K-T boundary? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
Words from Greek and Roman Mythology Quiz
-
- Boreal comes from the name of the ancient Greek god of which wind?
Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
-
Words from Greek and Roman Mythology Quiz
A mythological/etymological mashup!
Take the quiz -
Great Scrabble Words—A Quiz
Words to improve your Scrabble game
Take the quiz -
Name That Thing
Test your visual vocabulary with our 10-question challenge!
Take the quiz -
Bee Cubed
Listen to the words and spell through all three levels.
Play the game
Share K-T boundary
Resources for K-T boundary