dinosaurs

Cultural  

1. 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.

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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.

Example Sentences

"Dinosaurs go from being co-stars to the headliner," Srivastava said.

From Science Daily • Apr. 15, 2026

Field Station: Dinosaurs, which is shutting down in November after 14 years, put the creatures on Marketplace at an employee’s suggestion.

From The Wall Street Journal • Oct. 23, 2025

The new series of Walking With Dinosaurs starts on Sunday 25 May at 18:25 BST on BBC One, with all episodes available on BBC iPlayer.

From BBC • May 19, 2025

Dinosaurs are hardly ever found in their entirety, and this one is no exception.

From Los Angeles Times • Nov. 15, 2024

Dinosaurs to rocket ships: the oldest things, and the ones still in the future.

From "A Heart in a Body in the World" by Deb Caletti