Itombe Formation, Angola, 88 Million Years Ago

    Daylight collapses on the Late Cretaceous horizon. Fading remnants of its reddish light glistens across the waters of the West African coast. The sea appears endless when looking beyond, yet it's only a small part of the early South Atlantic. With the night approaching, the surface of the seawater appears dark and translucent.

    Hiding within the darkness below is an ecosystem untouched by the world above. Peering light reveals a plethora of oceanic fish of many shapes and sizes. Their darting and gliding add to the bubbling and rushing heard in the water, which otherwise would be silent.

A massive field of flowing greenery blankets the muddy, rock-infested floor. It appears like a collective of underwater vegetation, yet are plants formed by green algae. They take many forms such as leaves connected to narrow stalks, thin blades like grass or even misty green clouds clumped onto rocks. As with any plant on land, this sea foliage rests on the submerged ground soaking up light from above. This process aids in photosynthesis allowing these clumps of algae to grow and multiply.

    However, there are other organisms here that prevent the overspreading of this field of green. Black, spike-covered sea urchins inch across the floor between all the sea plants. They only move at a snail's pace, but large groups can clear away 30 feet of these underwater plants in nearly a month. Even now, bits and pieces of the greenery are being chewed away by these spiny invertebrates.

    These urchins too have an adversary controlling their populations. Hovering through the greenery are several Angolachelys, a type of ancient sea turtle. Much like their modern counterparts, they sport a hard shell and four flipper-like limbs. These shells are primarily dark green, the same as the algae, with lines of beige forming hexagonal shapes. The skin on their bodies has the same beige color but with hard, hexagonal scutes whose color matches their shell.

    Another trait Angolachelys share with modern sea turtles is a hard beak on their mouths. These hard, sharp structures are perfect for shearing apart their primary food source, the sea urchins. Normally, the long spines of these small creatures would deter many predators from even touching them. However, the turtles simply bite off these structures, clearing them away before crunching down onto the shells of the urchins. Not only do the Angolachelys get a constant food source, but the field of algae plants gains a reduced risk of being entirely depleted.

    Of course, this feeding isn't entirely constant. As reptiles who evolved on land, the turtles still have lungs and thus need air to breathe. So, now and then, they'd float up to the surface to draw oxygen into their gaping mouths before diving back down.

    Other forms of life lie concealed under the beds of flowing green, slowly feeding off of it. Clams bury themselves in the sand, occasionally consuming passing particles of algae. Barnacles suctioned to the rocks repeatedly open and close their mouths as green specs are sucked in. Marine snails slither across the floor and rocks, vacuuming up whatever they can of the bloom.

    In the greenery, a predator emerges to feast on the snails. A crab, bright red on its top while the rest is a creamy beige. It's none too dissimilar to the crabs seen in our modern waters as they are part of a lineage that goes as far back as the Triassic. Using their claws, they grasp and compress their prey, before nibbling at what's left over.

    This feasting gradually pauses as the crab stares upward. A wavering display of glowing white and dark green flashes above it. Captivated by the moving patterns, the ancient crustacean crawls toward it. The mass of glimmering color seems to grow larger as it approaches the dazed decapod. Suddenly, four, long tentacles spring from the mass and pull the crab toward it. The flashing stops as the appendages encapsulate the hard-shelled animal while four others flow loosely.

    These floppy, fleshy tentacles belong to an organism higher in the local food chain than the crab. It's a type of ammonite, a 25-centimeter-long female Scaphites named Safara. Like other members of her famous group, she is a type of cephalopod related to squids, cuttlefish, and octopuses.

As such, she sports eight long tentacles growing from a soft, boneless body. These appendages hide a sharp, parrot-like beak that breaks apart even the toughest prey like the shell of a crab. It also can produce a lethal venom that kills those unfortunate to fall in her Safara's grasp, though would be ineffective against larger organisms. On both her left and right sides rests a single eye with a black, w-shaped pupil, each one moving independently from the other. The bottom of her body is a fleshy tube that helps to create gusts of water with which she moves through the sea. Thanks to cells called chromatophores, her skin can change into a variety of colors. Right now, her skin is primarily a dark green to blend with the algae around her while the edges of her tentacles have a bright white.

    Unlike her modern relatives, her body sticks out from a hard shell. As a Scaphites, however, the shape of this shell is unique compared to the spiral form seen in other ammonites. It instead has a loose shape, resembling the number 9. This structure is primarily light brown with dark, orange bands over the ridges across the shell.

    Safara's kind has a massive range worldwide, from as far north as Greenland to as far south as the Antarctic. This algae field near the coast of Angola is just one of a few that she and many others travel to. However, feeding isn't her only purpose here.

    Once finished consuming the crab, Safara ascends above the field of algae. She spots other female Scaphites poking up from the greenery, upwards of over a hundred. As they rise, their colors swiftly shift to a dark red.

***

    Night finally arrives and the only light entering the water is that from the moon. Even after nearly an hour, Safara and the other female Scaphites remain hovering above the field of aquatic greenery. Her eyes dart back and forth, searching the pitch-black waters around her.

    Soon, she spots the very thing she and the other females had been awaiting. Emerging from the shadows around the algae plants are over a hundred male Scaphites. Their appearance is very similar to those of the females, but with an average length of over 40 centimeters, they're much larger. Unlike the females, they have several white bands across their tentacles and the fleshy parts of their bodies. This and their bright blue coloration signal that they are ready for the imminent occasion they've gathered here for: mating.

    Right away, several males start to swarm around each of the females. All the suitors flash an array of vibrant blues, greens, and whites across their skin in an attempt to woo a would-be mate. At the end of the day, however, even the most colorful of displays aren't what guarantees a partner. More often, it's the largest and fittest of males that have the greater chance of passing their genes to the next generation.

    Safara learns this first-hand as she's already attracted the attention of a massive male. At 50 centimeters long, Jelani is easily the largest Scaphites here at this gathering. Yet, his presence doesn't halt the approach of other males, eager to mate with Safara. In response, the large male charges toward the rival suitors, sometimes even bashing them with his shell by accident.

Often, Jelani would also swarm his tentacles around the bodies of more daring males and deliver bites onto their flesh. The results are so drastic that entire tentacles can be lost. While it may appear to be a horrible consequence, it's only a minor issue for Scaphites. Like other cephalopods, they can regrow lost tentacles. So, in time, it will appear as if nothing had happened.

Through his sheer size and aggression, Jelani commands dominance over Safara. Even the few males that remain anywhere near him maintain a considerable distance away from the massive suitor. Nonetheless, a sign appears on Safara that kills Jelani's chances with her. A thick, white stripe appears on the side of her body nearest to the large male. This display signals that she no longer has the desire to mate with him. Although the large male continues to hover over her to deter rivals, he stays farther away than he did before.

As Jelanai further drifts upward, another Scaphites approaches. This time, the massive male pays it no mind as it appears like the other females in coloration. Unbeknownst to him, the individual that lies underneath his view isn't a female, but rather a younger, smaller male named Emene. Through a combination of his size and changing the appearance of his skin, he can give off the appearance of a female. This tactic has deceived mighty Jelani, making him think that Emene is a potential mate of his rather than another rival. Now, the mimic is free to woo Safara while the goliath above chases off other competitors.

Hidden in the algae field and the shadow of Jelani, Emene shows off his courtship colors. Bands of white, blue, and green dance across his skin, creating a dazzling display. Promptly, Safara's pigment pulses with white, signaling her acceptance of the sneaky male. Right away, they wrap their tentacles together, appearing to conjoin their mouths. Under these tentacles, Emene had begun the process of transferring his sperm, passing that would contribute to the next generation. The act is brief, ending as they let go after a minute.

As they do, giant Jelani directs his attention to the pair. Emene still sports his female colors used to deceive him. Thus, the large male gradually approaches him, opening his tentacles as he prepares to mate. The mimic backs away, revealing his true colors before jetting away.

Emene is only one of many that Safara will mate with during this gathering. She will carry the sperm of multiple males here, ensuring the greatest genetic diversity for her offspring. This process will be taxing for her many partners, none of which she'll see again after the night is over.

***

Nearly two weeks have passed and midnight arrives once again. The full moon has hit its peak in height, its white light barely penetrating the black waters off the coast of Angola. This slight shimmer reveals a different part of this West African cove.

Here, colliding waves at the surface create intense clouds of white, submarine foam. Algal plants are far less common, only being found in sparse clumps clinging to the sides of various stones. These underwater rocks come in many shapes and sizes. Many of them help to make up various canyons, caverns, and crevices. The gaps in them are so dark that even the silty sand at the bottom is completely hidden.

It's also above these rocks that Safara and the many other female Scaphites began to gather. Having finished mating, they are all pregnant and ready to lay their eggs. To do so, they must spawn in a place where predators wouldn't easily find them.

That is where the submerged rocks come in. To many of the other organisms that reside here, the gaps between the stones are too small to enter. Female Scaphites are just small enough to enter and still have room to lay their eggs.

Indeed, this ancient cove is the perfect place for spawning but even a haven such as this has dangers lying in the wait. As Scaphites instinctively come here every breeding season, so too do other creatures native to these waters. Though they don't come here to spawn, rather they come to feed.

The first of these animals burst from the larger caverns, catching a Scaphites in its mouth. This is an ancient shark called Ptychodus. Its name means "fold teeth," referring to its most unique feature. Rather than having sharp, pointed teeth like most sharks, it has over 500 flat ones, shaped like garbage can lids. Such a different adaptation makes it perfectly adept at crushing hard prey like the shells of ammonites. These odd teeth rest in the mouth of a short, wide-gaped head at the tip of a streamlined, fusiform body, resembling a bull shark. It's, however, much larger at 33 feet in length. The smooth skin of this shark is light brown at the top while its underside is completely white.

With prey in its jaws, the Ptychodus starts to grind up the helpless Scaphites. Crunches and cracks fill the water as it chews up the shell and flesh of the ammonite. Carapace shards from the shark's victim gently float onto the stones and into the crevices below.

While the Ptychodus munches on its catch, Safara and the other Scaphites scatter throughout the water in search of crevices to fit themselves into. As they do, four more predators rush toward some of the ammonites, clasping mouths onto the shells of those unfortunate to be caught. They're not sharks, but rather a different kind of aquatic hunter.

These are Angolasaurus, members of the mosasaur family of carnivorous marine reptiles. At up to 13 feet long, they're quite small compared to their much larger, more well-known relatives such as Mosasaurus and Tylosaurus. Their heads are proportionately long with mouths filled with over 20 sharp teeth. Four large, paddle-like limbs help steer their stream-lined bodies through the water while their long, flat-tipped tails with flukes propel them. Their skin is made up of keeled scales, the top half being a silvery blue with their underbelly completely white.

While the teeth of Angolasaurus aren't efficient at crushing ammonite shells like those of a Ptychodus, they instead serve another lethal purpose. Their teeth puncture the shells of the Scaphites, leaving V-shaped rows of holes. Through these cracks, air escapes their carapace, causing them to lose buoyancy and sink to the surface of the rocks. Immobilized, any ammonite that falls victim to the bite of an Angolasaur is helpless as they are subsequently pulled out of their shells and gobbled up. Even then, these reptiles have a struggle with piercing their prey's carapace, making the process require multiple bites.

Between the single Ptychodus and the four Angolasaurs, many Scaphites unfortunately lose their lives. Although, many more can escape the chaos, finding refuge in the cracks and laying their eggs. Safara hasn't yet been so lucky as she's still being tailed by the Ptychodus.

With the shark growing ever closer, she employs her secret trick. A cloud of black ink erupts from Safara's body. Its color is so thick and dense that it completely blinds every animal caught in it, especially the Ptychodus. With the shark distracted, the clever Scaphites propels her way downward to the safety of the crevices.

Despite her escape from one predator, another quickly follows. Being the smaller predator, an Angolasaurus can more easily chase Safara through the bigger crevices of the underwater canyon system. She can't ink again as she doesn't have enough left in her to produce another cloud. With the reptile swiftly approaching, she can only continue jetting through the rocks.

Safara zooms and twists around every corner she comes across. So does the Angolasaurus, growing ever closer. As the predator approaches, the rocks around her rush by ever slower. Her body is waning and can't keep up such intense speed for long.

Only inches from the tiring cephalopod, the Angolasaur's jaws start to open. Safara's body begins to fall within biting range of her pursuer. Before the predator can chomp her, the ammonite makes one more jet out of its range. This time she doesn't propel forward but rather turns around. The Angolasaur attempts to react but ends up crashing into a stone wall.

It briefly shakes its head before turning around. The predator's eyes comb over the tight cracks of the rocks, finding no sign of Safara. It then starts to repeatedly stick its forked tongue out to smell the water around it, a method shared with the snakes and monitor lizards it's related to.

The Angolasaur's tongue only flicks thrice before it moves. Its senses draw it to one aperture in the rocky maze. As it passes, the predator's eyes search all across the stone walls and sandy sea bed. Even after half a minute, it seems to find nothing.

While it would stay longer to hunt further, one force keeps it from remaining for much longer: its biology. As a descendant of land-dwelling animals, it uses the lungs as its mode of respiration. Thus, it quickly rises through the maze and to the surface for air.

With the Angolasaur gone, all that seems to remain is stone and partial algae. One animal shows its shape as it pops off the rock walls. It's the familiar shape of Safara, her skin perfectly reflecting the black and partial green of the rocks around her.

Now, she is free to fulfill the goal of her journey. She shoots her precious cargo into a narrow, yet deep crack in the stone. Her eggs are gelatinous and white with a distinct tear-drop shape to them. For the value they hold, each one is incredibly small, no bigger than a grape. Shooting out from Safara's tentacled mouth, they instantly stick to the walls of the crack.

By the time Safara's egg-laying is finished, a few hundred of her fertilized offspring lay in their long stony hole. Finally, she ends the job by squirting a gust of ink onto them. These change the color of the eggs, allowing them to blend in with the rock and further hide from predators. With this added camouflage, the babies inside are free to develop until the day they hatch.

However, such a day is one their mother won't see. Safara and many other female Scaphites have succeeded in planting the seeds of the next generation. Even after evading predators to do so, they haven't escaped the grip of death. Like other cephalopods, ammonites live very short lives. Even Safara has only lived a single year before passing on. Coupled with the strain of mating and spawning, her body can no longer support her. Now the mother's corpse rests lifelessly on the seabed, moved only by the pull of the ocean's current.

If Safara's children are lucky enough, they too will live long enough to find a partner later in life and further continue to their lineage. With the many predators that would see them as potential food, such a chance is one that's never guaranteed. Though with as many eggs as there are even in this single crack in the stone, the odds are further supported that at least one or more of them will lay their own eggs, like their mother before them, here in Midnight Cove.