The Dinosaur Bone Collection

Sunday, August 1, 2010

Since their discovery over 150 years ago, dinosaurs have been a source of intrigue and fascination for young and old alike. The first dinosaur bones were discovered in Western Europe during the 1820s, but today their fossils are found on all of the continents and several hundred distinct types of dinosaurs have now been classified. Dinosaurs are a group of extinct reptiles that first appeared about 225 million years ago and became extinct about 66 million years ago. The reptilian nature of dinosaurs is evidenced by their skeletal features and the fact that they reproduced by laying hard-shelled eggs.

The skeletal features of many dinosaurs are remarkably similar to those of modern birds, which has led to speculation that dinosaurs are ancient ancestors of birds. The term "dinosaur" was coined in 1842 by British comparative anatomist Richard Owen, from the Greek words deinos meaning "terrible" and sauros meaning "lizard" or "reptile". Because dinosaurs are now extinct, we must examine and study their fossils to understand the history of this fascinating group of animals. Dinosaur fossils were formed over a period of millions of years in the environment that dinosaurs lived and died. Fossils are usually found amid rock formations located in areas that often yield clues to the climate and habitats in which dinosaurs lived.

The term fossil refers to any preserved remains or imprint of a living organism (usually ancient), such as a bone, shell, footprint, or leaf impression. Most of the dinosaur fossils found today are mineralized bones, but they also include footprints, tracks, eggs, skin impressions, stomach stones (known as gastroliths), and fossilized feces (known as coprolites). Fossilization usually occurred when a dinosaur died and was buried or covered over by a sediment of rock particles. We don't believe that dinosaurs had formal burial rituals, so most dinosaur remains were probably scavenged by other dinosaurs before becoming weathered and slowly covered by sediment. The soft tissues that were not eaten (skin, eyes, muscles, and internal organs) rotted away quickly leaving only the bones and teeth to become fossilized.


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