The New Dictionary of Cultural Literacy, Third Edition. 2002.
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.
‡ 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.”
