What are Dinosaurs? Why were dinosaurs so big? What did they eat, where did they live, and how did they raise their young? The following are some of the most frequently asked questions about dinosaurs with short description of the best answers for further exploring. Learning about dinosaurs can be tricky—there are so many of them, and there’s so much to know—but it’s a lot easier when the details are portioned out in a logical way.
What Is a Dinosaur?
People hang 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.
Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints. They first appeared during the Triassic period, between 243 and 233.23 million years ago, although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 million years ago; their dominance continued throughout the Jurassic and Cretaceous periods.
Why Were Dinosaurs So Big?
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 size?
Two key reasons are their bone structure and bad eating habits. Like modern birds, many dinosaur bones were hollowed out by air sacs extending from their lungs, meaning that a dinosaur would have weighed significantly less than a solid-boned mammal of similar size. It follows that dinosaurs could support a much larger body with their four legs – up to 80 tonnes in the case of the largest plant-eating sauropods (in comparison, today’s largest African elephants reach about six tonnes).
When Did Dinosaurs Live?
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 overview of the Mesozoic Era, the period of geologic time comprising the Triassic, Jurassic, and Cretaceous periods.
How Did Dinosaurs Evolve?
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 is a the story of the evolution of the first dinosaurs.
What Did Dinosaurs Really Look Like?
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 how their anatomy and posture are depicted but also the color and texture of their skin. Here’s a more detailed analysis of what dinosaurs really looked like.
How Smart Were Dinosaurs?
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.
How Fast Could Dinosaurs Run?
In the movies, meat-eating dinosaurs are portrayed as speedy, relentless killing machines, while plant-eating dinosaurs are fleet, stampeding herd animals. The fact is, though, that dinosaurs differed enormously in their locomotive abilities, and some breeds were faster than others.
How Did Dinosaurs Hunt Their Prey?
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.
Where Did Dinosaurs Live?
Like modern animals, the dinosaurs of the Mesozoic Era occupied a wide range of geographical regions, from deserts to tropics to polar regions, across all the Earth’s continents.
Dinosaurs lived on all of the continents. At the beginning of the age of dinosaurs (during the Triassic Period, about 230 million years ago), the continents were arranged together as a single supercontinent called Pangea.
Why Did Dinosaurs Go Extinct?
Dinosaurs went extinct about 65 million years ago (at the end of the Cretaceous Period), after living on Earth for about 165 million years. Scientists don’t agree on what happened, but the extinction likely involved an asteroid impact, choking chemicals from erupting volcanoes, and climate change.
At the end of the Cretaceous period, dinosaurs, pterosaurs, and marine reptiles seemed to have disappeared off the face of the Earth virtually overnight (though, in fact, the process of extinction may have lasted for thousands of years).