Advertisement
Advertisement
dinosaurs
- Reptiles , now extinct, that were the dominant life form on Earth for many millions of years. The name dinosaur comes from the Greek words for “monstrous lizard.” Dinosaurs became extinct suddenly, about sixty-five million years ago. Scientists now believe that their extinction was caused by the impact of a large asteroid on the Earth.
Discover More
Notes
Some dinosaurs were very large and had small brains — factors that may in part have led to their extinction. The term is often used to refer to something or someone that is antiquated and unable to adapt to change: “The old cavalry generals couldn't adjust to the use of tanks — they became dinosaurs.”
Some scientists believe that modern birds are the descendants of dinosaurs.
Commonly known dinosaurs include Tyrannosaurus rex , Brontosaurus , Stegosaurus, and Triceratops.
Advertisement
Word of the Day
[tawr-choo-uhs ]
Meaning and examplesStart each day with the Word of the Day in your inbox!
By clicking "Sign Up", you are accepting Dictionary.com Terms & Conditions and Privacy Policies.
Advertisement
Advertisement
Advertisement
Browse