The Big Book of Facts

Facts 221-230,Dinosaurs

221. Dinosaurs were reptiles that lived on Earth from about 230 million years ago to about 65 million years ago.

222. Dinosaurs lived during a period of Earth's history called the Mesozoic ("middle life") Era. They lived during all three periods of this era: the Triassic, Jurassic, and Cretaceous.

223. No one knows exactly how long a dinosaur's lifespan was. Some scientists speculate some dinosaurs lived for as long as 200 years.

224. Dinosaur skulls had large holes or "windows" that made their skulls lighter. Some of the largest skulls were as long as a car.

225. Dinosaurs lived on all the continents, including Antarctica.

226. While many people think dinosaurs were massive, dinosaurs were usually human sized or smaller. Scientists believe that the larger bones were just easier to be fossilized.

227. Some dinosaurs' tails were over 45 feet long. Most dinosaurs had long tails that helped them to keep their balance when running.

228. The word "dinosaur" was coined by British paleontologist Richard Owen in 1842. It is Greek, meaning "terrible lizard." Rather than implying that dinosaurs were fearsome, Owen used the term to refer to their majesty and size.

229. The first dinosaurs that appeared during the Triassic Period 230 million years ago were small and lightweight. Bigger dinosaurs such as Brachiosaurus and Triceratops appeared during the Jurassic and Cretaceous periods.

230. The earliest named dinosaur found so far is the Eoraptor ("dawn stealer"). It was so named because it lived at the dawn of the Dinosaur Age. It was a meat eater about the size of a German shepherd. The first Eoraptor skeleton was discovered in Argentina in 1991. However, another dinosaur has recently been found in Madagascar that dates as being 230 million years old. It has not been named yet.