Terrible lizards. that's what the word “Dinosaurs” means. yet dinosaurs are not true lizards, and they are not necessarily terrible either. What they are is endlessly fascinating—and still able to surprise us.

Paleontologists have overturned one misconception after another: As it turns out, dinosaurs were not necessarily sluggish and cold-blooded. Many dinosaurs had feathered skins long before the origin of birds. And not all dinosaurs were enormous: some were less than a foot long. Others, of course, grew to be more than 100 feet long, and growth lines in dinosaur bones are providing clues about how quickly these animals reached full size, as John R. Horner, Kevin Padian and Armand de Ricqlès explain in “How Dinosaurs Grew So Large and So Small.” Even in the American West, where many of the earliest discoveries were made, there have been surprises. We now know, for example, that distinct communities of ancient behemoths once shared a relatively small landmass; Scott D. Sampson writes about their lives in “Dinosaurs of the Lost Continent.”

We still have much to learn about dinosaurs: the details of how they looked and sounded, exactly what they ate, and what kind of interactions they had with one another and with other species. For example, although recent research has revealed that Tyrannosaurus rex could bite down with tremendous force and then rake its teeth deeply through flesh and bone, paleontologists still are not sure whether T. rex was primarily a predator or a scavenger, as Gregory M. Erickson points out in “Breathing Life into T. rex.” 

Calling someone a dinosaur is supposed to be an insult, but it's a misguided one. These amazing creatures ruled the earth for tens of millions of years. Scientists now realize that even the long-necked, small-brained sauropods—once seen as awkward also-rans—thrived for nearly 150 million years; go to “Triumph of the Titans,” by Kristina A. Curry Rogers and Michael D. D'Emic, to learn about their secrets for success. Modern humans, by comparison, have been around for only a couple of hundred thousand years. And although most dinosaurs perished in a massive extinction about 66 million years ago, technically they are still around: Birds not only evolved from dinosaurs but also lived alongside them for a while, as Gareth Dyke writes in “Winged Victory.” Some birds managed to survive the mass extinction.

Like the dinosaurs before us, humans are now the dominant species on the planet, but we, too, could face extinction—if not from an asteroid impact, then perhaps from precipitous climate change or nuclear warfare. Dinosaur fossils provide us with tantalizing hints of the fragility of existence—and of the capacity for adaptation.