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

"So Megalosaurus, Cetiosaurus and other dinosaurs would have been living on these little islands."

From BBC • Jun. 10, 2026

Fast facts: A sci-fi thrill ride starring Anne Hathaway and Ewan McGregor as parents who have to fight for their lives when their whole street is mysteriously transported to a world with dinosaurs.

From The Wall Street Journal • Jun. 6, 2026

The world was filled with unusual creatures experimenting with body shapes and lifestyles that often resemble modern animals or later dinosaurs.

From Science Daily • May 29, 2026

In George Redfox’s photography class, Cervantes and his classmates were assigned to take pictures of mini dinosaurs on the ground at varying angles.

From Los Angeles Times • May 29, 2026

Perhaps the smart bipedal dinosaurs, or the raccoons, or the otters, or the squid.

From "Cosmos" by Carl Sagan