12 Frequently Asked Dinosaur Questions

The Most Commonly Asked Questions About Dinosaurs

Why were dinosaurs so big? What did they eat, where did they live, and how did they raise their young? Here's a list of the dozen most frequently asked questions about dinosaurs, complete with links to additional information.

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What Is the Definition of a Dinosaur?

tyrannosaurus rex
The skull of T. Rex, a dinosaur of the late Cretaceous period (Wikimedia Commons).

People sling the word "dinosaur" around an awful lot, without knowing precisely what it means--or how dinosaurs differed from the archosaurs that preceded them, the marine reptiles and pterosaurs with which they coexisted, or the birds to which they were ancestral. In this article, you'll learn what experts really mean by the word "dinosaur."

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Why Were Dinosaurs So Big?

Nigersaurus (Wikimedia Commons).

The biggest dinosaurs--four-legged plant eaters like Diplodocus and two-legged meat-eaters like Spinosaurus--were bigger than any other land-dwelling animals on earth, before or since. How, and why, did these dinosaurs attain such enormous sizes? Here's an article explaining why dinosaurs were so big.

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When Did Dinosaurs Live?

mesozoic era
The Mesozoic Era. UCMP

Dinosaurs ruled the earth longer than any other terrestrial animals, all the way from the middle Triassic period (about 230 million years ago) to the end of the Cretaceous period (about 65 million years ago). Here's a detailed over of the Mesozoic Era, the period of geologic time comprising the Triassic, Jurassic and Cretaceous periods.

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How Did Dinosaurs Evolve?

Tawa (Nobu Tamura).

As far as paleontologists can tell, the first dinosaurs evolved from the two-legged archosaurs of late Triassic South America (these same archosaurs also gave rise to the very first pterosaurs and prehistoric crocodiles). Here's an overview of the reptiles that preceded the dinosaurs, as well as the story of the evolution of the first dinosaurs.

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What Did Dinosaurs Really Look Like?

Jeyawati. Lukas Panzarin

This might seem like an obvious question, but the fact is that depictions of dinosaurs in art, science, literature and movies have changed radically over the last 200 years--not only as concerns their anatomy and posture, but also the color and texture of their skin. Here's a more detailed analysis of what dinosaurs really looked like.

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How Did Dinosaurs Raise Their Young?

titanosaur egg
A titanosaur egg. Getty Images

It took decades for paleontologists just to figure out that dinosaurs laid eggs; they're still learning about how theropods, hadrosaurs and stegosaurs raised their young. First things first, though: here's an article explaining how dinosaurs had sex, and another on the subject of how dinosaurs raised their young.

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How Smart Were Dinosaurs?

Troodon (London Natural History Museum).

Not all dinosaurs were as dumb as fire hydrants, a myth that has been perpetuated by the spectacularly small-brained Stegosaurus. Some representatives of the breed, especially feathered meat-eaters, may even have attained near-mammalian levels of intelligence, as you can read for yourself in How Smart Were Dinosaurs? and the 10 Smartest Dinosaurs.

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How Fast Could Dinosaurs Run?

Ornithomimus, aka the "bird mimic" (Julio Lacerda).

In the movies, meat-eating dinosaurs are portrayed as speedy, relentless killing machines--and plant-eating dinosaurs as fleet, stampeding herd animals. The fact is, though, that dinosaurs differed enormously in their locomotive abilities, and some breeds were faster than others. This article explores how fast dinosaurs could really run.


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What Did Dinosaurs Eat?

A Cycad. Wikimedia Commons

Depending on their proclivities, dinosaurs pursued a wide variety of diets: mammals, lizards, bugs and other dinosaurs were favored by meat-eating theropods, and cycads, ferns and even flowers figured on the menus of sauropods, hadrosaurs and other herbivorous species. Here's a more detailed analysis of what dinosaurs ate during the Mesozoic Era.

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How Did Dinosaurs Hunt Their Prey?

Deinocheirus. Luis Rey

The carnivorous dinosaurs of the Mesozoic Era were equipped with sharp teeth, better-than-average vision and powerful hind limbs; their plant-eating victims evolved their own unique set of defenses, ranging from armor plating to spiked tails. This article discusses the offensive and defensive weapons used by dinosaurs, and how they were employed in combat.

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Where Did Dinosaurs Live?

riparian forest
Riparian forest. Wikimedia Commons

Like modern animals, the dinosaurs of the Mesozoic Era occupied a wide range of geographical regions, ranging from deserts to tropics to polar regions, across all the earth's continents. Here's a list of the 10 most important habitats prowled by dinosaurs during the Triassic, Jurassic and Cretaceous periods, as well as slideshows of the Top 10 Dinosaurs by Continent.

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Why Did Dinosaurs Go Extinct?

barringer crater
The Barringer Crater. U.S. Geological Survey

At the end of the Cretaceous period, dinosaurs, pterosaurs and marine reptiles disappeared off the face of the earth virtually overnight (though, in fact, the process of extinction may have lasted for thousands of years). What could have been powerful enough to wipe out such a successful family? Here's an article explaining the K/T Extinction Event, as well as 10 Myths About Dinosaur Extinction.