Debunking Five Myths About Dinosaurs

A grand tour of dinosaurs, from one of our most prolific natural history writers. I’ve been reading Donald Prothero’s books since I began studying geology in college, and here he delivers again, with a romping chronicle of some of the most charismatic dinosaurs and the equally fascinating people who have studied them.

~Steve Brusatte, University of Edinburgh paleontologist and New York Times best-selling author of The Rise and Fall of the Dinosaurs

Dinosaurs are huge these days, thanks to the success of the Jurassic Park/World movies and gigantic volumes of dinosaur merchandise and TV shows, even for preschoolers. Sadly, however, most of what people think they know about dinosaurs is incorrect—and much of it can be attributed to the misleading images in the same movies that helped make dinosaurs so popular. Today, author Donald Prothero, a professor of geological sciences at California State Polytechnic University in Pomona, is setting the record straight on some of the most common myths about these cretaceous creatures in the post below. Prothero’s new book, The Story of the Dinosaur in 25 Discoveries: Amazing Fossils and the People Who Found Them is now available.

Enter our drawing for a chance to win a copy of the book!

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© N. Tamura
  1. All dinosaurs were huge.

The gigantic dinosaurs were indeed the largest creatures ever to live on land, but most dinosaurs were much smaller, and many of them (such as the nasty “compys,” or Compsognathus in the Jurassic Park movies) were the size of chickens.


2. Dinosaurs all lived at the same time.

Dinosaurs ruled for over 150 million years and lived on every continent, and the assemblages of dinosaurs evolved constantly. Most of the dinosaurs in the Jurassic Park/World movies did not meet each other in the real world, and most lived in in the Cretaceous—but author Michael Crichton thought the name “Jurassic” sounded better. To put this in perspective: Tyrannosaurus rex was closer in time to us than it was to the plate-backed, spike-tailed Stegosaurus, which is frequently shown battling it.


3. Dinosaurs were stupid, lumbering examples of obsolescence.

The word “dinosaur” is often used as a put-down for something or someone who is outdated, obsolete, and inflexible. But dinosaurs ruled for over 150 million years before the end of the Cretaceous, were incredibly diverse and successful, and evolved rapidly to fill many ecological niches. If something had not happened to end their reign, there is no reason to think they would not still dominate the planet—and that we would not be here.

4. Mammals pushed out the dinosaurs when they evolved at the end of their reign

Actually, mammals and dinosaurs appeared at the same time about 216 million years ago, and for 150 million years, they evolved side-by-side—but mammals hid in the underbrush and came out at night, never getting larger than the size of an opossum (and most were shrew-sized). Only after extraordinary events took out the dinosaurs 66 million years ago did mammals inherit an Earth without large animals to compete with, and they evolved into today’s large diversity of creatures from shrews to bats to monkeys to whales. But almost two-thirds of the history of mammals occurred while the dinosaurs dominated.

5. The impact from an asteroid was not the sole cause of dinosaur extinction.

Yes, a rock from space did hit Yucatán in Mexico about 66 million years ago and caused “nuclear winter” conditions on Earth—but this was also the time of the second biggest volcanic eruption in Earth history, when enormous volumes of lava and gases poured out of what is now western India and Pakistan, changing the climate. The fossil record shows that most of the animals at that time (including dinosaurs) were vanishing or already extinct long before the impact event.

So the next time you see dinosaurs portrayed in movies or on TV, remember that most of it is incorrect or just made up. They are entertainment, not science. And enjoy the songs of the dinosaurs in your garden.

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