Evolution

The suchomimus, toying with her fish, saw the wall of darkness bear down once more. But this time it came from inland, and it was laden with debris, with dirt and rocks and uprooted trees and even a huge male tyrannosaur that writhed lifeless, high in the air.

Once more the suchomimus dived at the sand.

From the furies of the crater the shock front continued to spread out, like a ripple around a fallen stone. Further inland, where Giant had raided the tyrannosaur nest, the front had wrought devastation around a great circle big enough to have been wrapped around the Moon.

Tornadoes spun off the advancing front like willful, destructive children.

To Giant, the twister was a tube of darkness that connected sky to ground. At its feet, what looked like splinters rose up, whirled and fell back. The giganotosaurs’ ancestors had invaded a continent. Now Giant reared up and hissed, bobbing his head, eyes triangulating on the approaching menace.

But this was no saurian competitor. As the twister approached it grew ever larger, towering high above him.

At last something in Giant’s mind focused on those twigs scattered at the feet of this climatic monster. Those "twigs" were trees, redwoods and ginkgoes and tree ferns, scattered as easily as pine needles.

His brothers made the same calculation. The three of them turned and ran.

The base of the twister tore casually through the blanket forest, destroying trees, scattering rock. Animals weighing five tons or more were hurled into the air, great slow-moving herbivores suddenly flying. Many of them died of shock even before they hit the ground.

In her burrow, Purga was shaken awake by the rattling of the earth. She and her mate huddled closely around the two pups, and they listened to the howling of the wind, the clatter and crunch of trees being shattered, the scream of dying dinosaurs.

Purga closed her eyes, baffled, terrified, longing for the noise to stop.

And in the foothills of the Rockies, the mother azhdarchid sensed the approach of the mighty wind. Hastily she folded up her wings and waddled on wrists and knees toward her nest.

Her young clustered around, but she had no food to give them, and they pecked at her angrily. The chicks were still flightless, their wing membranes yet to develop. For now they had only loose, useless flaps of skin trailing between their flight fingers and hind legs. And yet they were already beautiful, in their way; the scales that clustered around their thin necks, a relic of their reptilian ancestry, caught the high sunlight, gleaming and glistening.

But now clouds raced across the sun. The twisters would not reach so high. But the shock front was still a broiling wall of turbulent air, still powerful even so far from the impact site.

A first gust buffeted the nest. The chicks screeched and stumbled.

Without thinking the mother flapped her wings, taking to the air. A primitive imperative had taken over. There would always be more broods, if she survived. The chicks, receding beneath her, squawked their anger and fear.

As the wall of wind approached, there was a moment of stillness.

The azhdarchid’s airspeed dropped. She turned and spread her wings, instinctive responses coming to play. She held out her long flight finger and her hind limb, and subtle twitches of thigh and knee adjusted the tension in her wings. She was an exquisite flying device, an apparatus of tendons, ligaments, muscle, skin and fur, shaped by tens of millions of years of evolution.

But the comet wind didn’t care about that, not at all.

The wind hit the nest first. The rock ledge was swept bare, the nest smashed to fragments. The bones of the pterosaurs’ victims — including those of Second — were sent whirling into the air with the rest of the debris. The chicks flew: if only briefly, if only once, if only to their deaths.

And then, for the mother azhdarchid, it was as if she had flown into a wall of dust and spray, and even bits of vegetation and wood and rock. She felt her fragile bones snap. She was tumbled over and over, helpless as a dead leaf.

Once more the suchomimus struggled to her feet. She ached in her legs, arms, back, tail, and head, where she had been struck by bits of flying debris, the wreckage of a world.

Again the beach had become an utterly unfamiliar place. The ground was now littered by debris from inland, bits of smashed trees and crushed animals, dead or dying pterosaurs and birds, even lake-bottom ooze. Nothing moved — nothing but dying creatures, and the suchomimus.

She remembered the fish she had been about to eat. The fish was gone.

Above her, dark banks of cloud whipped across the sky, like a curtain being drawn. The sun disappeared; it would not be seen again for a long time.