Evolution

The crocodile had been a messy killer. The mud of the shore was left soaked in blood, and littered with scraps of the suchomimus — lengths of glistening entrails, chunks of ripped flesh, even its staring, dismembered head. The first scavengers on the scene were a pack of small, agile raptors; they burst from the undergrowth, hopping, jumping, and swiveling, lashing out at each other like kickboxers as they fought over the juicy scraps of flesh.

They were soon joined by pterosaurs, flapping in noisily. They landed on the mud and walked clumsily, with legs and elbows splayed like a bat’s. Their heads were long, their beaks narrow and equipped with sharp teeth. The beaks dug deep into the remnants of the suchomimus. As more pterosaurs were attracted, the sky became darkened by their gaunt wings. One pterosaur in particular descended toward the two toiling primates.

Purga saw it coming. Second did not.

His only warning was a gush of leathery air, a glimpse of huge, hair-covered wings flapping across the sky above him. Then clawed feet fell out of the sky and enclosed him like a cage.

It was over before Second knew what had happened. From the comforting noises of the ground he was lifted into a silence broken only by the rustle of the pterosaur’s huge flapping wings, the silky straining of its wirelike muscles, and by the rush of the wind. He glimpsed the land, dark green and pocked by blue-glimmering ponds, falling away beneath him. And then the view opened up spectacularly to the southeast, the direction where the comet lay. The comet’s head was a vast unearthly lantern hanging over the tongue of sea that pushed into the land from the Gulf of Mexico.

Second longed only to get out of this cage of scaly flesh, back to the ground and his burrow. He thrashed at the talons that contained him, and tried to bite into the flesh; but the scales of the huge creature defied his small teeth.

And the pterosaur squeezed until small primate ribs cracked.

The pterosaur was an azhdarchid. She was the size of a hang glider. Her massive, toothless head, with a pointed triangular beak at the front and an elaborate crest at the rear, was sculpted to serve as an aerodynamic aid. Her hollow bones and porous skull made her remarkably light, and her body was tiny. She was nothing but wings and head. She looked like a sketch by Leonardo da Vinci.

The spar of each pterosaur wing was a single tremendous finger. Three remnant fingers created a small claw in the middle of the leading edge. The wing was held open by her hind legs. With all four limbs occupied in controlling the aerodynamic surfaces, the azhdarchid’s relatives could never diversify, like the birds, into running or aquatic forms. But the pterosaurs had been astonishingly successful. Along with birds and bats, they had been one of only three groups of backboned animals to have mastered flight — and they had been the first. By now pterosaurs had darkened Earth’s skies for more than a hundred and fifty million years.

The azhdarchid was capable of taking fish from shallow waters, but made most of her living as a scavenger. She rarely took live mammals. But Second — who had been engrossed in devouring a worm he was pulling from the sand — had not realized how visible the bright comet light had made him. He was not the only animal whose rhythms and instincts were disturbed by the new light in the sky. He had been an easy capture.

Second lay still, encased in pain, as cold air washed over him.

He could see the great outstretched wings above him, comet light shining blue through the translucent skin. Tiny creatures squirmed: a pterosaur’s wing was an enormous expanse of almost hairless skin packed with blood vessels, a powerful lure for parasitic insects. Every square centimeter of the pterosaur’s wing surface was controlled by an underlying mat of muscle fabric, enabling the azhdarchid to control her aerodynamics with exquisite precision; her body was a better engineered glider than any manufactured by human hands.

The azhdarchid banked to avoid a smudge of volcanic cloud that hung above the young mountains. It would be fatal for her delicate wings to be caught in such foul air. She was expert at spotting upwelling fountains of warm air — marked by cumulus clouds or over the sun-facing slopes of hills — that she could exploit for free lift. To her the world was a three-dimensional web of invisible conveyor belts, capable of carrying her anywhere she wanted to go.

The azhdarchid’s nest was in a foothill of the Rockies, above the tree line. A steep wall of young rock soared above a guano-stained ledge littered with eggshells and bones and beaks. Chicks stalked noisily around this confined area, scattering the bits of shells from which they had emerged a few weeks earlier. There were three of them; they had already devoured a weakling fourth sibling.