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

With the longtime teacher’s approval, Cervantes and a friend kept a pair of dinosaurs; one was named Tom, and the other Jerry, inspired by the show Cervantes loved watching with his dad growing up.

From Los Angeles Times • 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

Scientists have identified a massive new species of mosasaur, a marine reptile that lived alongside the dinosaurs and dominated prehistoric oceans.

From Science Daily • May 23, 2026

The researchers discovered that dinosaurs with shorter arms tended to have especially robust skulls.

From Science Daily • May 20, 2026

Several other opportunities arose for Americans to claim the discovery of dinosaurs but all were wasted.

From "A Short History of Nearly Everything" by Bill Bryson