Meg: Hell's Aquarium (2 page)

It would be an innovation that would lead to mass diversification, separating predator from prey, instantly reshuffling the ocean’s food chain. The planet’s first true hunters evolved, and with them the wolves of the sea—the sharks.

For many species of fish, the Panthalassic Ocean quickly became a dangerous place to live.

Necessity is the mother of invention, adaptation the means to survival. One hundred seventy million years after the first vertebrates hatched in the sea, a lobe-finned fish crawled out of the Panthalassa onto shore . . . and gasped a breath of air. Gills would evolve into nostrils and internal lungs, ventilated by a throat-pump. Within 20 million years these new animals had colonized the land.

The age of amphibians had arrived.

Adapting to a terrestrial lifestyle demanded more evolutionary changes, propelled by the need to survive more efficiently. Limited by their need to re-hydrate, amphibians developed a rib cage that allowed for expansion and contraction while increasing the volume of air that could be processed by the lungs. Changes in internal fertilization and the composition of the egg shell further protected the developing embryo from drying out.

Sixty million years after the first lobe-finned fish crawled out of the sea, the first reptiles were born.

More anatomical adaptations would follow. Positioning of the hip girdle gave some reptiles the ability to stand and run on their hind legs. Skull weight was reduced with the addition of new temporal openings that replaced heavy bone with tendon-like materials. These openings also served to increase the bite power of the jaws . . . and a new subclass of reptile rose to prominence—the dinosaur.

By this time, Pangaea had separated into two continents—Gondwana and Laurasia. As the planet’s landmasses continued to break apart and drift, the Panthalassic Ocean divided into the Atlantic and Arctic Ocean basins and, eventually, the Indian and Pacific Oceans. Changes in atmospheric and geological conditions would lead to global warming and ice age cycles, affecting the inhabitants of both land and sea. The survivors evolved into the next dominant species; the weak dead-ended into extinction.

While the dinosaurs ruled the land and air, another subclass of reptiles—the placodonts and ichthyosaurs—returned to the ocean. These were the planet’s first true sea monsters; the long-necked
Elasmosaurus
; the massive-skulled
Kronosaurus
;
Shonisaurus
, a sleek, dolphin-like, fifty-foot, forty-ton
Ichthyosaurus
; and the largest beast of all—
Liopleurodon
.

Over the next 170 million years these fearsome predators would dominate the land and sea . . . until one fateful day, 65 million years ago, when a seven-mile-in-diameter hunk of rock fell from the sky and, once again, everything changed.

The firestorms brought on by the asteroid strike caused a global nuclear winter of sorts by emitting caustic gasses and millions of tons of ash and soot into the atmosphere, blotting out the sun. The fires subsided, giving way to an ensuing ice age that officially ended the age of the dinosaurs, sparing only those species that could adapt to the sudden drop in temperatures.

But there were other planetary changes going on as well.

Earth’s continents and ocean floors rest on a giant jigsaw puzzle of crust known as the lithosphere. Composed of fourteen massive tectonic plates and thirty-eight minor ones, the lithosphere floats over our planet’s hot interior like a constantly moving glacier. These movements are driven by volcanic forces that appear along the plates’ boundaries—the engine behind the planet’s drifting continents.

When molten rock (magma) pushes up through the sea floor, it forces tectonic plates to spread apart, or diverge, creating valleys known as rifts. Should two or more continents collide, the result is an upheaval that creates mountain ranges. When the collision occurs underwater, the denser of the two tectonic plates slips beneath the lesser at the subduction zone, creating deep fissures, or trenches—the deepest parts of the ocean. The denser plate melts into magma, reemerging as erupting lava, which leads to the formation of island chains.

Nowhere are these volcanic interactions more evident than along a minor lithospheric plate known as the Philippine Sea Plate.

Forming the basin beneath the Philippine Sea, shaped like a diamond, the Philippine Sea Plate is unique in that it is completely surrounded by subduction zones. Bordering the plate to the east is the massive Pacific Plate, which is converging and subducting beneath its geology, forming the Mariana Trench, the deepest gorge on the planet. To the west is the Eurasian Plate, to the south the Indo-Australian Plate, and to the north the North American, Amurian, and Okhotsk plates—each tectonic border forming a deepwater trench.

With an average depth of 19,700 feet, the Philippine Sea Basin represents the most unexplored, isolated region on our planet, its tremendous pressure making it inaccessible to all but the world’s deepest-diving submersibles.

Scientists have had to rely on bathymetric equipment in order to obtain any kind of significant data on this ancient geology. In the process, they failed to discover the sea plate’s true anomaly—an isolated sea, hidden deep beneath the basin’s crust, that dates back to the Panthalassa. Harbored within this enclosed habitat is a thriving food chain that has sustained primitive life since the very first marine reptile returned to the ocean over 240 million years ago.

It moves effortlessly through depths’ perpetual darkness, its albino hide casting a soft glow along the silent sea floor seven thousand feet below a tempest surface. Streamlined from the tip of its blunt bullet-shaped snout to the upper lobe of its powerful half-moon-shaped caudal fin, the fifty-eight foot, thirty-ton behemoth reigns over its habitat.

Concealed behind the barely visible gum line are hundreds of razor-sharp teeth, each edge serrated like a steak knife. The bottom teeth, totaling twenty-two, are stiletto-sharp, designed for puncturing and gripping prey. The wider upper quadrants, twenty-four in number, are powerful weapons capable of cutting and penetrating bone, sinew, and blubber. Behind the upper and lower front row are four to five additional rows of replacement teeth, folded back into the gum line like a conveyor belt. Composed of calcified cartilage, containing no blood vessels, these dentures are set in a ten-foot jaw that, instead of being fused to the skull, hangs loosely beneath the brain case. This enables the upper jaw to push forward and hyperextend open—wide enough to engulf, and crush, an adult bull elephant.

As if the size and voraciousness of its feeding orifice were not enough, nature has endowed this monster with a predatory intelligence honed by 400 million years of evolution. Six distinct senses expose every geological feature, every current, every temperature gradient . . . and every creature occupying its domain.

The predator’s eyes contain a reflective layer of tissue situated behind the retina. When moving through the darkness of the depths, light is reflected off this layer, allowing the creature to see. In sunlight, the reflective plate is covered by a layer of pigment, which functions like a built-in pair of sunglasses. While black in normally pigmented members of the species, this particular male’s eyes are a cataract-blue—a trait found in albinos. As large as basketballs, the sight organs reflexively roll back into the skull when the creature launches an attack on its prey, protecting the eyeball from being damaged.

Forward of the eyes, just beneath the snout, are a pair of directional nostrils so sensitive that they can detect one drop of blood or urine in a million gallons of water. The tongue and snout provide a sense of taste and touch, while two labyrinths within the skull function as ears. But it is two other receptor organs that make this predator the master of its liquid domain.

The first of these mid-to-long-range detection systems is the lateral line, a hollow tube that runs along either flank just beneath the skin. Microscopic pores open these tubes to the sea. When another animal creates a vibration or turbulence in the water, the reverberations stimulate tiny hairs within these sensory cells that alert the predator to the source of the disturbance miles away.

Even more sensitive are the hunter’s long-range receptor cells, located along the top and underside of the snout. Known as the ampullae of Lorenzini, these deep, jelly-filled pores connect to the brain by a vast tributary of cranial nerves. This “neural array” detects the faint voltage gradients and bio-electric fields produced by aquatic animals as their skin moves through the water, by the breathing action of their gills . . . or by their beating hearts. So sensitive is the ampullae of Lorenzini to electrical discharges that the creature, while moving through the depths of the Philippine Sea, could locate a thin copper wire connected to two D-size batteries if it were stretched from Japan to the Chinese mainland several thousand miles away.

Carcharodon megalodon:
prehistoric cousin of the modern-day great white shark. The alpha predator of all time, the Meg bears a ferocity and disposition that condemns it to a lone existence. And yet, while its numbers have dwindled over the last million years, members of the species have survived extinction by adapting—in this case by inhabiting the nutrient-rich, hydrothermically warmed waters of the Philippine Sea Plate’s trenches.

Ringing the creature’s gray-blue right eye and football-size nostrils are a series of gruesome scars that extend down to its upper jaw line and an exposed section of gum. These wounds, along with a near-lethal bite that stole a twenty-inch chunk from its six-foot dorsal fin were inflicted by a larger rival sibling many years earlier.

To the few humans who have crossed this adult male’s path and survived, the Meg is known as Scarface. To the sea creatures that lurk within its considerable range, its pale bioluminescent glow means death.

Scarface’s deformed mouth twitches as the sea enters its orifice, held open in a cruel, jagged smile. Driven by hunger, the predator has abandoned its ancestral birthplace in the Mariana Trench to stakeout the Western Mariana Trough.

Rising to the surface at night, it had attacked and killed a juvenile whale shark just outside the shallows of the Palau Atoll. But before it could complete its feeding, dawn had chased it back into the depths, its nocturnal eyes still quite sensitive to direct sunlight. For six hours it had circled a thousand feet below its bleeding kill. Then, growing impatient, the hunter had abandoned the whale shark to continue its westerly trek.

Scarface swims along the sea bed in water temperatures just above freezing, yet the warm-blooded goliath is not bothered by the cold. Running the length of the Megalodon’s body, sandwiching its spinal column, are two thick bands of red muscle that not only empower its massive keel and tail, but act like a giant radiator, driving heat into its circulatory system—an internal thermostat operating at a full fifty degrees higher than its skin temperature.

Though it travels in depths that would crush a marine mammal, the fish, lacking an air bladder, remains impervious to water pressure. Buoyancy comes from the Megalodon’s liver. Weighing more than 25,000 pounds, the organ is set internally in folded layers and contains a buoyant oil that allows for optimum maneuverability through any depth.