When the Earth turned and the air cooled and the dinosaurs settled into their nightly torpor, at their feet the dirt stirred. The creatures of the night emerged: insects, amphibians — and many, many burrowing mammals, rising like a tide of miniature life around the dinosaurs’ pillarlike legs.
This night Purga and her new mate traveled together. Purga, a little older and more experienced, led the way. A few centimeters apart, proceeding in cautious fits and starts, they made their way down the shallow slope toward the lake.
They did not usually forage together. But the weather had been dry, and the priority for both of them was to get a drink.
This part of America had endured a long, epochal drying. Here the relic of the ancient inland sea was a great stretch of swampy land, drowned by new sediment from the Rockies to the west, young mountains eroding almost as quickly as they were born. And in this time of relative drought, any standing water was a focus for animals large and small.
And so the lakeshore was crowded with dinosaurs.
Here was a herd of triceratops, three-horned giants with huge bony frills that covered their shoulder regions. They were like heavily armed rhinos, dozing in their loose circles, the adults’ ferocious horns pointing outward to deter any hungry, night-prowling aggressor.
There were many duck-billed hadrosaurs. Herds had gathered around this shallow lake, a bewildering, brightly colored array of them, and Purga and Second had to creep past forests of their great, immobile legs, like refugees in an immense sculpture park. Even now, as the duckbills slumbered, their unconscious snoring was a cacophony of deep and mournful hoots, honks, and cries; they sounded like fogbound ships.
At last Purga and Second reached the edge of the lake. The water had receded, and they had to cross a stretch of stony, half-dried pond-bottom mud, slick with mucus and sheets of green vegetation. In the eerie, still light, Purga drank quickly, her eyes wide and whiskers twitching.
Their thirst sated, the primates split up. Second began to track over the shallow beach, looking for the little piles of coiled sand that marked the presence of a worm.
Purga moved up the beach to the fringe of the scrub, following a more intriguing smell.
She soon found the source of the stink: a fish. It was lying in a heap of rusty fern fronds, its carcass shriveled within its silvery skin. Somehow stranded far from the water, it had been dead many hours. When Purga poked the fish’s skin it burst, releasing a voluminous, noxious stench — and a squirming mass of ghost-pale maggots. Purga plunged her paws into the carcass. Soon she was pushing maggots into her mouth; the salty goodies burst between her teeth, releasing delicious body juices.
But now another fish came flying over her head, to land deeper into the scrub. Startled, she flattened herself, whiskers twitching.
A dinosaur was standing stock-still in the shallow water. She was tall and upright, some nine meters tall, with a jaw like a crocodile’s and a great purple-red sail on her back. Her teeth were hooked, and her hands were equipped with claws like great blades all of thirty centimeters long. Suddenly she plunged her claws into the water, breaking the glimmering surface into shards. A handful of silvery fish flew up, wriggling and squirming, and the dinosaur skillfully snapped most of them out of the air with her long mouth.
This was a suchomimus, a specialist hunter of fish. Her kind was a relatively recent immigrant from Africa, having traveled the land bridges that sporadically connected the continents. She dragged for fish like a bear. She could take her prey with her claws or by scooping her crocodilian jaw through the water, relying on her hooked teeth. She was hunting in the night — when most creatures of her size had become dormant — because now was the time when the fish, lulled by the dimming of the daylight, came to the surface and the shore to feed.
Some meters behind her, a second suchomimus followed. This was a male; like many hunting dinosaurs, the suchomimus traveled in mating pairs.
The female suchomimus swiped again, and fish rained onto the dry shore, where they flopped briefly, suffocation quickly extinguishing their pinpoint sparks of consciousness. But the female suchomimus ignored such easy takings, apparently preferring the game of the hunt.
As did the watching deinosuchus.
The deinosuchus was a giant crocodile. She glided through the water of the lake, almost silent, hidden from view by a thin surface layer of aquatic fern. Her transparent eyelids slid over yellow eyes, keeping the tiny green leaves away.
This deinosuchus was a female: already sixty years old and twelve meters long, many of her offspring had grown to hunters themselves. A time like this — a time of drought, a time when animals came clustering to the water, in their thirst losing some of their native caution — was a bonus time for the crocodiles, a time of easy pickings. But the deinosuchus was a creature capable of taking on a tyrannosaur; she seldom went hungry, whatever the weather.
The crocodiles were already ancient, descended from bipedal hunters some hundred and fifty million years before. They were supremely successful, dominating the shallow waterways and lakes all over North America and beyond: They were among the few animals of the Cretaceous to die of old age. And they would survive to the time of humans and far beyond.
The exquisitely adapted nostrils of the deinosuchus could sense the motions of the suchomimus pair at the edge of the lake. It was time. Her mighty tail flexed once.
Purga saw a kind of eruption at the edge of the lake. Pterosaurs and birds rose from floating nests, cawing throatily in protest. The male suchomimus barely had time to turn his expressionless head before the crocodile’s jaws locked around one of his great hind legs. The crocodile hauled backward, bringing the suchomimus crashing to the mud, crushing his beautiful crest. The suchomimus hooted and fought, trying to bring its long, bloody claws into play. But the crocodile slithered back toward the water, taking the suchomimus with her.
Barely a minute after the deinosuchus had emerged, the turbulence of its passing soothed away from the surface of the water. The female suchomimus seemed baffled by her sudden loss. She patrolled the water’s edge, hooting mournfully.
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.
The parent worked a spur of bone in her wrist that changed the shape of the wings’ membrane: like air brakes, this enabled her to slow without stalling. She came to a halt a meter above the ledge, and dropped onto her hind legs. She stowed her delicate wing membranes, folded her flight fingers across her back, and walked forward, her knees bent outward and her elbows bent.
Second was dropped. He clattered against bare rock. He glimpsed the adult azhdarchid flap away. He scrabbled at the rock, but it was too hard to burrow into.
And little monsters closed in on him, blue-black in the comet light. Fed by their parents’ proteinaceous offerings of fish and meat, the chicks were growing quickly. But their wings were still undeveloped, and their bodies and heads were relatively large. They looked like miniature dinosaurs.
The first beak nipped at Second’s hind leg, almost playfully. The scent of his own blood evoked sudden memories of the burrow. He experienced a kind of regret. He bared his teeth. The ravenous chicks closed around him. It was over in a heartbeat, his warm body torn apart.
But now something moved, far above the mother azhdarchid. She twisted her sketch of a head to peer upwards. In these tall Cretaceous skies, fueled by the oxygen-rich air, a pyramid of predators had erected itself, with all the savagery of its landbound analogues. But when she saw the vast sprawled shadow, skimming over the comet-bright sky
It was only an air whale.
The largest flying animal ever discovered by humans was a type of azhdarchid christened Quetzalcoatlus. Its wingspan of fifteen meters was four times that of the largest birds, condors; it had looked like a light airplane.
But the greatest pterosaur of all was an order of magnitude larger again.
The air whale’s tremendous, delicate wings were one
He lived his life in that thin, high layer of air called the stratosphere, higher than the mountains, above most of the clouds. But even this far from the ground there was life: a thin ethereal plankton of insects and spiders, windblown. Sometimes mating swarms of midges, or even locusts, could be blown up into this lofty realm. This was the whale’s thin bounty, which he scooped endlessly into his vast mouth.
