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

252 million years ago, during a slice of time geologists call the Permian Period, our surroundings would have been barely recognizable. No ruined factories or other signs of people. No birds in the sky or mice scurrying at our feet, no flowery shrubs to scratch us up or mosquitoes to feed on our cuts. All of those things would evolve later. We

The constant supply of heat from the deep Earth is what powers Old Faithful and the other geysers.

At the end of the Permian, these were the real agents of doom, and they started a cascade of destruction that would last for millions of years and irrevocably change the world in the process.

the end of the Permian was a very bad time to be alive. It was the biggest episode of mass death in the history of our planet. Somewhere around 90 percent of all species disappeared.

There have been five particularly severe mass extinctions over the past 500 million years. The

one 66 million years ago at the end of the Cretaceous period, which wiped out the dinosaurs, is surely the most famous.

Life is resilient, and some species are always able to make it through even the worst catastrophes. The volcanoes erupted for a few million years, and then they stopped as the hot spot lost steam. No

Dinosaurs lived during three periods of geological history: the Triassic, Jurassic, and Cretaceous (which collectively form the Mesozoic Era).

The Earth formed about 4.5 billion years ago, and the first microscopic bacteria evolved a few hundred million years later. For some 2 billion years, it was a bacterial world. There were no plants or animals, nothing that could easily be seen by the naked eye, had we been around.

eventually some of them turned their fins into arms, grew fingers and toes, and emerged onto the land, about 390 million years ago.

these lineages survive today. The first, the pseudosuchians, later gave rise to crocodiles.

The second, the avemetatarsalians, developed into pterosaurs (the flying reptiles often called pterodactyls), dinosaurs, and by extension the birds that, as we shall see, descended from the dinosaurs. This group is called the bird-line archosaurs.

The same way that nothing really changes as you cross the border from Illinois into Indiana, there was no profound evolutionary leap as one of these dog-size dinosauromorphs changed into another dog-size dinosauromorph that was just over that dividing line on the family tree that denotes dinosaurs.

The first true dinosaurs arose some time between 240 and 230 million years ago.

the supercontinent we call Pangea, and the ocean we call Panthalassa.

Petrified Forest National Park, which should be on the itinerary of any dino-loving

Some 30 million years after they originated, the dinosaurs had yet to mount a global revolution.

SOME TIME AROUND 240 MILLION YEARS ago, the Earth began to crack. True dinosaurs hadn’t quite evolved yet, but their cat-size dinosauromorph ancestors would have been there to experience the cracking—except

photogrammetry, and it’s revolutionizing how we study dinosaurs. The super-accurate models it creates can be measured in precise detail.

The primitive proto-sauropods like Plateosaurus began to experiment with relatively large sizes in the Triassic, as some of them got up to about two or three tons in weight. That’s roughly equivalent to a giraffe or two. But after Pangea started to split, the volcanoes erupted, and the Triassic turned into the Jurassic, the true sauropods got much larger. The ones that left tracks in the Scottish lagoon weighed about ten to twenty tons, and later in the Jurassic, famous beasties like Brontosaurus and Brachiosaurus expanded to more than thirty tons. But that was nothing compared to some supersize Cretaceous species like Dreadnoughtus, Patagotitan, Argentinosaurus—members of an aptly named subgroup called the titanosaurs—which weighed in excess of fifty tons, more than a Boeing 737.

how were these dinosaurs able to attain sizes so completely out of scale with anything else evolution has ever produced?

it’s estimated that a big sauropod like Brontosaurus probably needed to eat around a hundred pounds of leaves, stems, and twigs every day, maybe more. So

they need to grow fast.

Third, they must be able to breathe very efficiently, so they can take in enough oxygen to power all of the metabolic reactions in their immense bodies.

they need to be constructed in a way that their skeleton is strong and sturdy, but also not so bulky that it can’t move. Finally, they need to shed excess body heat, because in hot weather it is very easy for a big creature to overheat and die.

sizes. The key seems to be their unique body plan, which is a mixture of features that evolved piecemeal during the Triassic and earliest Jurassic, culminating in an animal perfectly adapted for thriving at large size.

It all starts with the neck.

They could also park themselves in one area for several hours and extend their necks up and down and all around like a cherry picker, gobbling up

plants while expending very little energy. That meant they were able to eat more food, and thus take in energy more efficiently, than their competitors.

most sauropods matured from guinea-pig-size hatchlings to airplane-size adults in only about thirty or forty years,

all of the vertebrae were so engulfed by air sacs that they were little more than honeycombs, featherweight but still strong.

sauropods had lacked any one of these features—the long neck, the fast growth rates, the efficient lung, the system of skeleton-lightening and body-cooling air sacs—then they probably would not have been capable of becoming such behemoths.

150 million years ago. By this time, dinosaurs had already become the dominant force on land.

when the asteroid fell down from the sky 66 million years ago, putting a violent end to the Cretaceous, exterminating all of the nonflying dinosaurs.

means that all living things—modern and extinct—are related, cousins on one grand family tree.