The Dinosaur Book
The amazing variety of life that exists on our planet is so rich that new kinds of organisms are still being discovered every day. More than 2 million species (types of organisms) have been named and described by scientists, and there are probably millions more waiting to be discovered. But these are only a tiny fraction of the species that have ever existed on Earth in the past. If you were to go back in time 100 million years, you would find yourself surrounded by just as many different animals and plants as today, but—unless you had read this book first—you wouldn’t recognize any of them.
Until a little over two centuries ago, no one realized this. They thought that the animals they saw around them had always existed, and that the world hadn’t really changed over time. But in the late 18th century, scientists started examining strange shapes found in rocks and realized that they were fossils— the remains of ancient life that had been turned to stone. Most of these fossils were of seashells and other familiar forms, but some were dramatically different—huge bones, skulls, and teeth of gigantic animals that lived millions of years before the dawn of human history.
Using fossils that date right back to the beginning of life on Earth, about 3.8 billion years ago, scientists have been able to piece together most of the history of life. One of the most exciting parts of that story started about 230 million years ago with the earliest dinosaurs. Over the following 164 million years, these animals were to evolve into the most spectacular land animals that have ever walked the Earth. They included gigantic beasts that weighed as much as 12 elephants; terrifying hunters that could bite their way through solid bone; and strange creatures with horns, frills, and even feathers.
The giant dinosaurs were wiped out in a global catastrophe 66 million years ago. But their fossils survive, along with other fossils that show, beyond doubt, that many of their smaller, feathery relatives were able to fly. Some of these feathered dinosaurs survived the disaster to flourish in the new era as birds. So not only do fossils tell us about life in the distant past, they can also reveal astonishing facts about animals that we see all around us every day.
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|June 30, 2020|