The Rise and Fall of the Dinosaurs: A New History of a Lost World: The Definitive Dinosaur Encyclopedia with Stunning Illustrations, Embark on a Prehistoric Quest!

by Steve Brusatte

Rocks record history; they tell stories of deep ancient pasts long before humans walked the Earth. And the narrative in front of us, written in stone, was a shocker. That switch in the rocks, detectable perhaps only to the overtrained eyes of a scientist, documents one of the most dramatic moments in Earth history. A brief instance when the world changed, a turning point that happened some 252 million years ago, before us, before woolly mammoths, before the dinosaurs, but one that still reverberates today. If things had unfolded a little differently back then, who knows what the modern world would be like? It’s like wondering what might have happened if the archduke was never shot.

Absence of evidence is not always evidence of absence, as all good paleontologists must continually remind themselves.

The very foundation of Pangea was splitting, and with the blissful ignorance of homeowners who don’t realize there’s a creeping crack in their basement until their house comes tumbling down, the dinosaurs had no inkling that their world was going to dramatically change.

As with human relationships, things can get really nasty when a continent breaks up. And the dinosaurs and other animals growing up on Pangea were about to be changed forever by the aftereffects of their home being ripped in two.

So what’s a 1960s teenager to do when his favorite fossil site is being destroyed?

A trade secret among paleontologists is that many of the fantastical numbers you see in books and museum exhibits—Brontosaurus weighed a hundred tons and was bigger than a plane!—are pretty much just made up. Educated guesses or, in some cases, barely that.

A few years ago, Sasha showed me a new dinosaur fossil from Uzbekistan at a conference. He whisked me up to his room, ceremoniously opened an ornately colored orange-and-green cardboard box, and pulled out part of the skull of a meat-eater. He put the fossil back in the box and handed it to me so I could take it back to Edinburgh to CAT-scan it. But before he let go, he looked me in the eye and, in the Russian-accented drawl of movie bad guys, said, “Be careful with the fossil, but be even more careful with the box. This is Soviet box. They don’t make them like this anymore.” Grinning with mischief, he then pulled out a small bottle of dark-colored liquid. “And now we toast with Dagestan cognac,” he proclaimed, pouring two glasses, then another two, and then a third round. We toasted to his tyrannosaurs.

T. rex had a mouth full of thick, serrated, razor-sharp teeth. Its hands and feet boasted big pointy claws. There’s really only one reason an animal would have these things: they’re weapons, used to procure and process flesh. If your teeth look like knives and your fingers and toes are hooks, then you’re not eating cabbages.

There’s probably never a good time for a six-mile-wide asteroid to shoot down from the cosmos, but for dinosaurs, 66 million years ago may have been among the worst possible times—a narrow window when they were particularly exposed. If it had happened a few million years earlier or later, maybe it wouldn’t just be seagulls congregating outside my window but tyrannosaurs and sauropods too.

After the asteroid hit, there was probably no one thing that sealed the dinosaurs’ fate. They just had a lot of liabilities working against them. Being small, or having an omnivorous diet, or reproducing quickly—none of these things guaranteed survival, but each one increased the odds in what was probably a maelstrom of chance as the Earth devolved into a fickle casino. If life in that moment boiled down to a game of cards, dinosaurs were left holding a dead man’s hand. Some species, however, cashed in on a royal flush. Among them were our mouse-size ancestors, which made it to the other side and soon had the opportunity to build their own dynasty.