We didn’t always know so much about dinosaurs. A few hundred years ago, nobody even knew dinosaurs existed! Before the science of dinosaur study was really well-developed, people believed that the earth was just a few thousand years old. Most people believed that the only creatures that ever lived on the earth are the ones we know today. The first dinosaur teeth and bones were found in China about 3,500 years ago. The ancient Chinese thought these were the teeth and bones of dragons. They knew they were very old, but they didn’t know how old. Other bones and footprints were found in the 1600s and 1700s in Europe and North America. People at the time believed they were the bones of very large birds or giants from the Bible, such as Goliath. It wasn’t until the 1800s that people began to really study these bones carefully.
One of the first people to study rocks was a scientist named Charles Lyell. In the 1800s, Lyell published a book called The Principles of Geology. Based on the many rocks he had studied, and how they had changed, he decided that the earth was very, very old – much older than a few thousand years. Charles Darwin read his book and went to study animals. He wanted to see whether animals also changed over many, many years. He took a long trip on his boat, the H.M.S. Beagle. For five years, he sailed to far-away islands and studied many different kinds of strange animals. In 1859 Darwin published his book The Origin of the Species. Here, he wrote that animals could change into other animals over a long period of time. This is the theory of evolution and it would change science forever.
The first bones to be called dinosaur bones were found in England, in 1677, by Robert Plot. He had found a huge thigh bone of a large meat-eating dinosaur, but he didn’t know what it was. He thought it belonged to a giant! In 1824, William Buckland discovered the jawbone of another large meat-eating dinosaur. However, he decided that the bones belonged to a giant reptile that was no longer alive. He didn’t have many bones to work with. In fact, he only had the jawbone and some teeth, shoulder bones, a few back bones called vertebrae, and leg bones. But he decided that the bones belonged to a huge lizard that was no longer alive. He called the creature Megalosaurus and decided that it was about 40 feet long and seven feet high. That’s about as large as a small airplane. In the 1820s, an English doctor named Gideon Mantell found several fossils of a creature he called Iguanodon. He decided that it was about 60 feet long. While he wasn’t really correct, he still made one of the first drawings describing a dinosaur.
In 1838 Richard Owen made a long list of all the fossils that different people had found. He was the one who came up with the word “dinosaur”,which means “terrible lizard”. Later, more and more fossils and fossilized footprints were found in Colorado and Wyoming in the United States. A lot of different kinds of dinosaur bones were found: Allosaurus, Ceratosaurus, Apatosaurus, Diplodocus, Stegosaurus and Triceratops. By the early 1900s, dinosaur fossils had been found all over the world. Back then there was no way to find out how old these bones were. In the 20th century, scientists discovered how to use radiation to find out how old the bones were. People were amazed to discover that the bones they were digging up were over 65 million years old! This changed everything scientists thought they knew about the history of the earth. The study of paleontology was born.