Evolution

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.