Los Colorados Formation, Argentina, 212 Million Years Ago

It is early morning, and the sun casts its golden glare from a pale gray sky. Darker gray clouds drift through the air, casting a shadow off the late dawn radiance. The mix of shade and solar gleam projects onto what is now South America.

At this time, the land of Argentina rests at the lower west edge of the supercontinent of Pangea. Many of the major continental shifts that would split and contort the great landmass have yet to occur. Thus, the only form of high elevation is a series of smooth hills. Although this area is where the Andes mountains will one day be, no signs of them are present as they won't form until far in the future.

Below and between the hills is a system of crisscrossing rivers and streams. Waters carried in them flow in and out of lakes and ponds scattered between. The sounds of rabbles, ripples, burbles, and trickles emanate from them as clear liquid gently travels through them.

Surrounding these bodies of water is a plethora of plant life. Much of it is familiar to modern-day such as the many ferns, seed ferns, and conifer trees. The latter has yet to take a form recognized today, having a more primitive appearance. One plant, dicroidium, appears like a sycamore tree but is a type of seed plant ancestral to many modern gymnosperms.

One form of greenery is almost alien in appearance, like nothing humankind has ever witnessed. Their trunks are tall, slender, and upright with a crown of narrow-needle-like leaves arranged in a spiral pattern around the base. Resting at the top of each of these trunks are cone-like structure akin to what's seen on cycad plants, yet these plants, called pleuromeia, are unrelated. It's actually an ancestor of smaller, grass-like plants called quillworts.

Such an abundance of plant life is a rare sight outside of the more fluvial parts of this area. With temperatures of up to 86 degrees Fahrenheit common in the Triassic, this land has become hot and arid. Even here by the streams, the ground beneath the plants is brown, dry, and covered in small, gray pebbles.

Despite such scorched conditions, life continues to thrive in abundance. The smallest and most plentiful forms are the many dragonflies and damselflies. In varying numbers, they zoom above and hover around the plentiful rivers. The sounds of their rapid wing flaps and stridulations fill the air around these bodies of water.

These insects are the most familiar of the animals present here. This runs in contrast to the other creatures that reside here. Much of this fauna is scarcely like anything alive today.

Drinking from and stalking the streams are the occasional Neoaetosauroides. They're 10-foot-long, flat-bodied animals with bony plates on their tops and underbellies. This mosaic of meticulously interlocked armor creates a nearly impenetrable shield over their back and flanks. These fortress-like bodies are supported by four stout, powerful limbs, each ending in clawed feet. Such claws are sharp and strong, serving them well at digging. Smaller versions of their bony plates decorate their long, muscular tails. Resting on its short neck is a small head and a blunt, slightly upturned snout. Their jaws are equipped with sharp, leaf-shaped teeth, well-suited for gripping their prey such as insects and small lizards, but also for shredding vegetation like ferns. This runs in contrast with other members of the aetosaur order which are normally solely herbivorous, despite being evolutionary offshoots of crocodilians. Much of their scaly skin is primarily reddish brown except for their tan underbellies.

Hanging around the vegetation are herds of Coloradisaurus. These are early members of the prosauropods, a clade of dinosaurs that will one day give rise to long-necked sauropods like Brontosaurus and Brachiosaurus. At up to 10 feet in length, they're a small fraction of the gigantic sizes their descendants will eventually reach.

Unlike sauropods, their bodies are sleek, streamlined, and held up by a single pair of long, slender legs. Each of these powerful hind limbs ends with three large, clawed toes that help provide traction and stability. These legs also have a fourth toe with an exaggerated, backward-facing dew claw. Their forelimbs are still present but are shorter and more robust. They also have five-digit hands equipped with claws well-suited for grasping vegetation. However, such talons are only present on three of their five fingers. Counterbalancing their bodies is a single long, muscular tail that tapers to a point. Their slender, moderately long necks support triangular heads and are proportionately small yet have large eyes. These heads have jaws filled with serrated, leaf-shaped teeth, perfect for slicing any vegetation with its reach. Their scaly skin is primarily a muddy green with a dull brown underbelly.

Between crunches and snaps of their browsing, they fill the natural ambiance with rumbles, grunts, snorts, and bellows. Neoaetosauroides are mostly silent outside of the croc-like hissing and grumbling that occasionally comes when two of them bicker over food and territory.

Among these dinosaurs and reptiles is another animal, one with a dangerous legacy. A type of creature that simply rests near the edge of the river, their image reflecting off the water's surface. One day, they will give rise to the most fearsome carnivores in Earth's history. For now, however, these individuals start rather small.

This is a pack of three Powellvenators, small, early members of the theropod family of meat-eating dinosaurs. Such a lineage will eventually give rise to the likes of Allosaurus, Velociraptor, and T-Rex. But at up to 3 feet long and weighing no less than a cutting board, they are a small fraction of the size of their fearsome descendants.

Like all theropods, the Powellvenators are mainly bipedal, having long, powerful legs that hold them above the ground and allow them to move at swift speeds. These powerful hind limbs support a sleek, aerodynamic body with a deep yet narrow chest. Their forelimbs are much shorter and end with three clawed fingers. A long, straight, stiff tail helps to balance out their forms. Atop their long, slender necks is a small, elongated head with a pointed snout, large eyes, and jaws filled with sharp, serrated teeth.

The biggest of them is Jaime, a fully-grown male. Much of his skin is made up of scales colored in burnt umber and a cream underbelly. He also has a batch of feathers on his back that are taupe brown with a little bit of bright blue mixed in.

Accompanying him are two juveniles, a male named Mateo and a female named Martina. Each of them is only about one-and-half feet long, about half the size of Jaime. They have the same skin color but more feathers covering their body, primarily light brown with various taupe brown spots.

Just as how many dinosaurs start in the Triassic, the Powellvenators are quite small compared to the much larger animals they live beneath. Nonetheless, they still find their own ways to thrive in the conditions of their environment. How they do it is something that Mateo and Martina will soon learn firsthand.

At this point in time, the two juveniles are now 6 months old. As such, they are now old enough to learn from their father how to feed themselves. Though they still have yet to leave the care of their parents, this knowledge will serve them greatly when the time comes.

But if they are to find their next meal, it won't be here. Although the Coloradisaurus and Neoaetosauroides would make for excellent meals, they're both too much for just three Powellvenators. Each has size as their advantage with the latter having armor.

Thankfully, this isn't their true destination. Rather it's just a quick stop they'll be making to drink from the refreshing river water. Now that they've hydrated, the family of predators is ready to embark toward their objective, leaving through a batch of greenery toward the west.

***

Eventually, the Powellvenators reach a single hill away from the lowland streams. The terrain here is much drier, dominated by scorched brown earth with gray rocks and pebbles. What little vegetation is present is reduced to dry ferns and the occasional, single tree.

Although the ground vegetation is reduced in height, it's still tall enough to hide each of the Powellvenators. Periodically, they peer their heads above a single fern plant dashing to the next one. Both father and juvenile repeat the process as they sprint all across the vast surface of the hill.

Upon peering over one bigger fern, Jaime pauses before turning to his left. He lets out a pair of high-pitched hisses, prompting Mateo and Martina to rush to him. From here they can see the most prominent sight of the area.

In the middle of this hilltop is a field of large over 50 dirt mounds. Each has a hole in the center blocked off by piles of ferns. These act as a shade for the contents that lie within: eggs. Each of these nests has over 20 of these fragile structures packed tightly within them.

Inside each egg is the potential for the next generation. For the Powellvenators, they offer something else: food. The yolk inside contains various nutrients that are beneficial to those who consume them.

Of course, one would need to fetch them first. Jaime begins to set out toward the colony of nests. Mateo and Martina follow only to quickly be stopped by their father hissing at them. The youngsters are eager to feed but if they are to navigate this field of eggs effectively, they'll need to watch and learn from the professional.

While his offspring stay and watch from afar, Jaime darts between the ferns toward the nesting ground. He clings to the wall of one of the nests, its shadow shielding him from the scorching Triassic sun. His head peers past the sides of the mound, once to the left and again to the right. At each glance, all that can be seen is the many other nests that lay in the colony. Upon returning to the shade, he begins the climb up the side of the nest.

Suddenly, he freezes, just centimeters away from the top. He begins to hear deep, rumbling breaths that can even be felt in his bones. The same effect is found in the occasional thunderous footsteps that are mixed in. Slowly, he creeps his head just above the peak of the nest to find the source of such noises.

Treading amongst the colony of nests are a dozen Lessemsaurus. Much like Coloradisaurus, they are prosauropods. However, at nearly 40 feet long and weighing nearly 10 tons, Lessemsaurus dwarf many of their contemporaries. Their descendants will soon exceed their size in the Jurassic and Cretaceous, but here in the Triassic, they're the largest land animals on Earth.

Their bodies are massive and bulky with a deep, barrel-shaped chest and a muscular tapering tail. This form is supported by four columnar legs, similar to their later sauropod relatives. The two front legs are shorter like those of other prosauropods, giving them a slightly inclined posture. Their feet and hands are like those of their relatives like Coloradisaurus, but due to their massive weight, they can only stand when in bipedal posture. When walking and running, they maintain a quadrupedal stance, an echo of their more famous descendants. Their necks are impressively long and robust, held up in a graceful arch. A relatively small head is held up by these necks, sporting a blunt snout, large, round eyes, and filled with leaf-shaped teeth. Their rough, pebbly skin is a mix of earthy brown and stone gray, with a cream underbelly.

Every year, Lessemsaurus herds gather at this field to nest. With this annual production of the next generation always comes predators like Jaime to take advantage. Such opportunism is something that has yet to escape the nesting behemoths. Regularly, much of the herd would leave their future broods behind to forage in the lowlands where vegetation is more abundant. This serves the purpose of feeding themselves and acquiring more fern branches that prevent their eggs from being overheated by the sun.

While navigating the nesting grounds is still difficult, it's still the best time for Jaime and his offspring to sneak around and attempt to steal some eggs. He'll also need to employ an important strategy for this raid. From the cover of the one nest he's hiding behind, Jaime can see the Lessemsaurus sentries as they continue their patrol patterns. All he has to do now is wait for the right opening. If he chooses poorly, he can risk getting spotted thus ruining the raid.

From a distance, Mateo and Martina watch in both awe and curiosity at their father. They see Jaime reach his head into the nest before pulling out a single egg. He does so very gently as its shell is very fragile, only as thick as a human fingernail. Immediately, the father sprints from the nest, quickly reaching his offspring.

Jaime sets his prized egg down before biting into the shell. Such a choice of food is very risky to acquire. However, with high amounts of cholesterol and other nutrients, it's a meal that's more than worth the effort.

As their father gorges down on the delicious yolk, Mateo and Martina approach the egg. Their approach is met with a hostile hiss from Jaime. The two juveniles remain frozen still as their father stares them down, his mouth covered in slimy yellow yolk. While such aggression seems a little too much, it's the only way for Powellvenator parents like Jaime to motivate their brood into acquiring their eggs to feast on.

Prompted by their father's tough love, the pair spring toward the nest. Like their father before them, they sprint between larger ferns for cover amidst their approach. Upon reaching the Lessemsaurus nursery, Mateo and Martina each cling to the side of a different nest mount.

Carefully, each one peers around the sides and top of their chosen nest. At different angles, the youngsters observe the steady patrol of the Lessemsaurus sentries. Mateo remains still, carefully waiting for a moment when his chosen nest is out of sight of the guards.

Martina doesn't have such patience. With little hesitation, she pokes her head into her nest, attempting to clasp her mouth around an egg. Try as she may, her mouth constantly slips off the shell.

Suddenly, a crunching sound emerges from the egg. Its shell cracks open, causing yolk to ooze out of it. Then, Martina feels a gust of air down her back as she hears a deep huff. She peers upward, locking eyes with a Lessemsaurus.

The giant snorts before stomping its foot down next to the nest, shaking the very earth under Martina. It lets out booming rumbles followed by a low hiss as it approaches her. She swiftly retreats to the cover of a large fern. From there, Martina peers her head around to see the Lessemsaurus standing over the nest she abandoned.

While her heart continues pounding, the young female also spots something else from her green refuge. Behind the behemoth, Mateo silently treads between the nests. While Martina may have ruined her chances at her first stolen egg, she's also unwittingly created an opportunity for her brother to sneak further into the nursery. Even in chaos, Mateo's deliberate patience serves to his advantage.

The young male lurks through the shadows cast by both the nests and the Lessemsaurus sentries alike. His approach remains silent among the rumbling of the guards around him. He also continues to pause between nests, peering around them to observe the patrol patterns of the Lessemsaurus.

In his observations, Mateo finds that even without the company of his sister, he's not the only nest raider here. A Neoaetosauroides has already arrived at the outskirts of the nesting grounds, rustling through the top of one mount for an egg to steal. This attempt doesn't go unnoticed as a Lessemsaurus immediately charges at it before stopping to stomp the ground and growl at it. The Neoaetosauroides backs away while letting out a raspy hiss.

While the presence of the larger carnivore means more competition, there's still one advantage to it. With only so many Lessemsaurus patrolling the nesting grounds, not all of the nests will be under their watchful eye. Now that one is preoccupied with the Neoaetosauroides, Mateo seizes his chance to approach another nest and tries to to steal from it.

As the young male climbs up the side of the mount, he starts to feel something clasp on his leg and tug him on him. He hisses as he drops down the side of the nest. Upon landing on his back, Mateo's met by a strange animal standing on top of him.

Standing on top of the young male Powellvenator is a 20-inch-long Tessellatia. Its head is relatively large with a short broad snout and small whiskers behind its flaring nostrils. Pulled-up lips expose a mouth filled with a mix of canine and incisor with molars further down the back of its jaws. It stands on four short, yet muscular legs held semi-erect under its sleek, slightly elongated body. A short, slightly tapering tail juts out from its back end. Its entire form is covered in a thick, solid gray coat of fur. It may appear like a mammal, but it's instead a member of the cynodont clade, a group of reptiles that resemble and are ancestral to mammals.

Pinning Mateo down, the Tessellatia stares down the young male Powellvenator. Saliva drips from its mouth as it hisses at him. This mammal-like reptile is also here to feast on eggs, but it won't be willing to share.

Suddenly, Mateo kicks the Tessellatia off of him, kicking up a small cloud of dirt in the process. The reptile stands back up as the young male Powellvenator rises upward above it. They engage in a battle of hisses as they constantly step toward and away from one another. The Tessellatia also squeaks in a manner akin to its more mammalian descendants.

Despite the ferocity displayed by both nest raiders, their conflict is broken by something larger than both of them. Abruptly, a Lessemsaurus emerges from behind the nest and stomps its foot down between them. Both Mateo and the Tessellatia are shooed away by the giant rumbling and growling at them.

The two each escape in opposite directions, taking refuge behind a different nest mount. Cautiously, Mateo sneaks his head out from the side of his nest, finding the Tessellatia doing the same thing. The mammal-like reptile squeaks at him, prompting the young male Powellvenator to hiss back.

Their audible altercation continues until the Tessellatia gradually stops. It gazes upward as its legs quiver. Swiftly, the reptile retreats, leaving the nesting grounds behind altogether. Mateo steps out from behind the nest, tilting his head as he witnesses the running Tessellatia.

Suddenly, he starts to hear an unfamiliar noise, an almost gurgling growl. It's not anything made by a Lessemsaurus but it's something similarly large. Mateo quickly finds himself engulfed by the mysterious animal's shadow, prompting him to dash behind one of the nests. Peering from the side of the mount, he spots the massive creature treading across the nesting grounds. Even the Lessemsaurus guards keep a distance from it in their attempts to intimidate it.

This is a Fasolasuchus, the top predator of this Triassic landscape. It's not a dinosaur, but rather a type of ancient, carnivorous cousin of crocodiles called a rauisuchian. With a maximum length of 33 feet and weighing up to 3 tons, it's easily the largest of its group and the biggest non-dinosaur land predator known thus far. Although this sub-adult is only 28 feet long, it still easily exceeds its other relatives in size.

Its muscular, heavily built body sports a broad, barrel-shaped torso. Four stout, powerful limbs support its weight. At the end of each of these legs are strong feet with sharp, curved claws. A long, thick tail tapers to a point and helps to counterbalance its heavy front body. Its short, well-built neck supports a large, boxy head with a broad snout. This head also has a set of jaws filled with large, serrated teeth, perfect for slicing through flesh. Its skin is made up of thick, scaly armor with bony plates on its back and flanks. This same skin is also a mottled brown across its body with lighter shades on top and darker ones on its underside and middle area.

As the Fasolasuchus strolls through the nesting grounds, the Lessemsaurus stomp and rumble at it to fend it off. They have reason to fear it as these behemoths are a common part of this predator's diet. Despite their efforts, the carnivore doesn't flinch in its approach.

Fearful of the land croc's presence, Mateo watches as the Fasolasuchus treads through, waiting for the opportunity to escape. Gradually, however, it stops and begins to sniff the air. Much like modern crocodilians, Fasolasuchus has well-developed olfactory lobes. So, even if it can't see potential prey, it can smell it.

It only takes a few sniffs before the Fasolasuchus pauses. The predator's head makes a steady swivel to its left as it picks up an odd scent. It does not belong to any of the Lessemsaurus guards or even their eggs. Rather, it's something much smaller.

Mateo stands frozen as he sees the Fasolasuchus approaching his way. As the largest terrestrial predator on land, it easily outsizes the young male Powellvenator. With no choice left, he leaves the nest behind, sprinting as fast as his legs will carry him.

However, such speed doesn't stop Mateo from catching the eye of the Fasolasuchus. It hastens its approach, running like a Cuban crocodile. The predator's body bounces up and down as it picks up momentum. Lessemsaurus sentries growl and rumble at the two as they sprint and maneuver around them.

Before long, Mateo manages to escape the nesting grounds with the Fasolasuchus trailing not far behind. Both Jaime and Martina peer up from different ferns to see their approach. The young male lets out a screeching hiss as the land croc's opening jaws draw ever closer.

In a split second, Mateo makes a swift turn narrowly dodging the Fasolasuchus' closing mouth. The predator stops, its feet leaving scuff marks on the earth. It begins to sniff the air as it turns around.

Behind one of the ferns, Mateo remains hidden alongside Martina. In their anxious yet silent state, they hesitate to even move a muscle, let alone take a look to see if the carnivore is gone. Of the two, the young female decides to do so. Upon first glance, all she spots is the dry land of the hilltop with the nesting grounds in the distance. Not even the youngsters' father is easily visible.

Suddenly, a clawed foot falls in front of Martina's face. She jumps and lets out a fearful screech. Mateo springs up, frantically turning his head back and forth alongside his sister.

These panicked movements turn into quivering as they hear a familiar gurgling growl. The siblings turn their heads upward, steadily and hesitantly. They're met with the sight of the Fasolasuchus standing over and looking down at them. Its jaws creep open as it prepares to take a lethal bite.

Suddenly, it stops and instead lets out a hiss. The predator pivots around in response to a pain in its left hind leg. It soon lays eyes on Jaime biting at its rear limb. In response, the land croc snaps its jaws at the adult Powellvenator, only for him to sprint away to the west. The Fasolasuchus swiftly follows, pursuing Jaime into a stretch of lowland forest. With both the predator and their father gone, Mateo and Martina act on their instincts and escape to the east.

In the thick underbrush, Jaime continues to sprint away from the predator. Bits of ferns slap against him as he speeds through. The same happens to the Fasolasuchus, but neither is deterred.

Abruptly, in the middle of the greenery, the land croc gradually starts to slow. Ceasing its running, it positions itself in the shadow below a handful of trees, panting heavily. The Fasolasuchus may be a massive and powerful predator, but it also faces the same limits many reptiles do. As a cold-blooded animal, it can only be active for so long before it needs to stop entirely. Its sheer size also means that it runs a bigger risk of overheating. Effectively immobilized, all the carnivore can do now is stand still while its body cools off.

The only movement it makes is its throat pulsing as it pants and its eyes darting as it looks around for Jaime. Amidst the thick vegetation, no sign of the adult Powellvenator is visible. Even his scent has been masked by that of the abundant plant life here. Puzzled and tired, all the Fasolasuchus can do is let out a loud hiss before walking away.

***

Further in the east lies a similar-looking, yet different grove of vegetation. This one lies right on the edge of one of the many ponds separating the lowlands. There's also a hole near the edge of the water, one that both Mateo and Martina arrive at.

Immediately, they're greeted by an animal emerging from the hole. It's another Powellvenator, an adult female named Abril. She appears similar to Jaime but lacks the blue coloring seen in the plumage of males.

Upon seeing the two youngsters, she rubs her head against them. Mateo and Martina welcome the gesture with similar head rubs while making purr-like noises. This isn't just any adult female Powellvenator but their mother.

The family's rubbing ends quickly as Abril peers her head above her offspring. She turns and swivels while letting out a series of hissing calls. They echo and reverberate with no response to be heard. The siblings do the same, only to be met with the same results. The Powellvenators call out more only to be met yet again with silence.

Suddenly, the silence is broken by a familiar sound. It's a call similar to the ones Abril, Mateo, and Martina have been making but it didn't come from any of them. From the rustling underbrush on the opposite end of the river, Jaime emerges. The rest of the family sprints toward him, splashing up water as their feet splash through the shallow stream. They greet each other yet again with gentle head rubs. Now tired yet reunited, the Powellvenators crawl through the hole in the ground and into the comfort of their burrow.

As is the case with many animals, there always comes a time in a young Powellvenator's life when they'll learn how to find food for themselves. Such a trial is not easily passed, where failure can cost a youngster their life. Thanks to the efforts of parents like Jaime and Abril, such a challenge is one they won't need to overcome alone. With further teachings, Mateo and Martina will know how to effectively navigate the struggles that come with living below the beasts.