Chapter 11: After
Earth 251 million years ago, a world in a state of recovery. Just a million years earlier, the Great Dying ravaged our planet, ending not just the Permian Period, but also the Paleozoic era as a whole. Currently it is the dawn of a new era, the Mesozoic, the middle chapter of the Phanerozoic Eon. Right now we are in a period known as the Triassic, the first of the 3 periods that will make up the Mesozoic era. Currently the Earth is still in rough shape, for while the Siberian Traps have finally burned themselves out, their effects are still being felt and will continue to be felt for millions of years to come.
Currently the supercontinent Pangea still stands and the massive deserts formed by the Siberian Traps have not receded. The heat from the sun continues to beat down on the planet with temperatures soaring to 140 fahrenheit in many cases. The interior of Pangea is still mostly uninhabitable for most organisms. In these brutal conditions, recovery will take a long time, for it will be another 30 million years before life on land even begins to approach the diversity it had before the Great Dying. In the water a different story is being told.
While the extinction was bad for terrestrial organisms, life in the seas fared even worse initially. Many of the great Paleozoic families saw either tremendous losses in diversity, or were even completely wiped out. Despite these tremendous losses, life in the seas is destined to recover more quickly than life on land, however the makeup of these new seas will be very different from what they were in the Paleozoic. While life in the seas bounces back, the few organisms left on land are also trying to pick up the pieces and recover, for while life in the interior is basically an impossibility for the larger organisms, there are still pockets of habitat left in certain places, take for example what is now South Africa.
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The sun rises across the landscape signalling the dawn of a new day. This area is a semi arid region, with seasonal swings. Before the Great Dying this region was a lush floodplain, however, that is no longer the case. While this area isn't a full on desert, it can get extremely dry during the dry season and currently the dry season is in full swing. The dominant type of flora here are horsetails.
Before the Great Dying there was a massive variety of plants that covered this region, but now that is no longer the case. The dry conditions of much of Pangea has left very little habitat for ferns and cycads among other plants and they are now restricted to coastal forests. Horsetails themselves are better adapted to drier conditions like these and they now cover the area. Horsetails themselves, are very tough plants and many herbivores would struggle to eat them. This has only contributed to the extinction of many herbivorous species.
The surviving herbivores have had to adapt to feeding on plants like these and one herbivore in particular has become very good at just that. A series of calls signals the arrival of a herd of Lystrosaurus curvatus. Lystrosaurus were among the survivors of the Great Dying and they have become the most successful of them all. Lystrosaurus can be found all over the world and make up an impressive 90% of the Earth's megafauna, never before and never again will a single genus be so successful. Surviving the Great Dying was not easy even for Lystrosaurus and they have had to make multiple concessions to survive.
One of the most noticeable adaptations is the smaller size of the Triassic Lystrosaurus species compared to their Permian ancestors. This smaller size evolved in response to the brutal conditions and on top of this, Triassic Lystrosaurus reach adulthood far more quickly allowing them to reproduce more quickly. All of this combined with their burrowing ability and their ability to hibernate through rough conditions gave these beasts a keen edge compared to other herbivores, including other dicynodonts, most of whom have not survived into the Triassic. The Lystrosaurus begin to forage snapping up horsetails with their power jaws and sharp beaks. Right now it is a race against the clock for the Lystrosaurus, soon the temperature will soar and it will become too hot for the herd to feed.
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A few minutes go by and the Lystrosaurus continue to chow down ravenously, unfortunately for them they are not the only survivors of the Great Dying trying to find a meal and some of their fellow survivors are perfectly adapted to hunt them. Watching from some ferns, is a hungry Moschorhinus. Moschorhinus is a therocephalian and one of the few of its kind to have survived into the Triassic. The Moschorhinus eyes the herd, looking for any sign of weakness. It spots an older female who looks to be in poor health.
The Moschorhinus gets into position, its relatively short limbs, combined with its stocky build means that it isn't built for long distance running, so it must get as close as possible to the Lystrosaurus. The Moschorhinus slowly creeps closer and closer to its prey, patience is necessary in all of this. Finally the Moschorhinus gets close enough and it bursts from the ferns. The Lystrosaurus has no time to react, as the Moschorhinus jumps on it and drags it right to the dirt. The Moschorhinus then clamps down on the Lystrosaurus throat sealing the herbivore's fate.
The Moschorhinus skull and jaws are short and packed with powerful muscles, giving them a lethal bite. The rest of the herd scatters rapidly with the attack, however, they will calm down in a few minutes, once the Moschorhinus disappears. The Moschorhinus quickly grabs its kill and it begins to haul it to a nearby burrow that it has dug out. During the Permian, Moschorhinus was not the top dog of this region, for it faced competition from larger predators like the gorgonopsids and this is where this behavior originates from. Of course this behavior proved useful for surviving the Great Dying as it allowed Moschorhinus to hide away in burrows, plus like Lystrosaurus they too have the ability to hibernate during tough times.
Another similarity to Lystrosaurus, is that they too have shrunk in size compared to their Permian ancestors and they also exhibit more rapid growth. Soon the Moschorhinus reaches its burrow and it drags its kill into the burrow with it. The Moschorhinus soon begins to feed on the carcass. After eating its fill, the Moschorhinus proceeds to begin resting, after all no one wants to be out during the day.
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Elsewhere, we find ourselves at one of the rivers that runs through this area, at this time of year the river is quite low and much of its bank is exposed. The river itself is often filled with activity, as the many footprints here can attest, albeit currently most of the animals are preparing to rest through the midday heat. In spite of this, there is one animal that has come down for a drink, meet Thrinaxodon liorhinus. Thrinaxodon itself is a cynodont and was one of the first creatures to evolve in the aftermath of the Great Dying. Thrinaxodon itself like most cynodonts live in the shadow of larger predators, as a result they have taken up a niche of being a small opportunistic animal, feeding on whatever it can find.
Normally Thrinaxodon sleep in burrows during the day like most creatures, however, for unknown reasons this one has made a late arrival at the river. The Thrinaxodon quickly quenches its thirst before scurrying back to its burrow. The Thrinaxodon quickly arrives at its burrow and it quickly descends into it. As the Thrinaxodon enters the burrow, it finds an unusual sight, for it seems that someone else has intruded. Lying on the blanket of moss, is a Broomistega, a type of temnospondyl.
Temnospondyls saw massive losses during the Great Dying, however, a select few survived the extinction event and they are now clinging on like every other creature. This particular Broomistega is a juvenile and he has internal rib injuries, what caused these injuries is unknown, however, in response he has set up shop in the burrow. The Thrinaxodon is unsure of what to make of its guest. He studies the amphibian intently, the Broomistega itself isn't much of a threat and removing it would likely be a great big hassle and so the Thrinaxodon decides to tolerate the little amphibian for now. The Thrinaxodon quietly lies down and begins to rest.
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Soon the midday sun begins to beat down with all its might, as most of the native fauna hide out away from the harsh conditions. After a time, the sun begins to set in the sky, while the temperature begins to drop. As the temperature drops, many of the animals awaken from their midday rest as they resume their activities. The Lystrosaurus are among these and they are quick to begin foraging once more. This evening, the Lystrosaurus are joined by some of their neighbours, among these are a type of animal known as Procolophon.
Procolophon are a type of parareptile, meaning they are related to the now extinct pareiasaurs, however, Procolophon is part of its own distinct family within the parareptiles. Procolophon itself is an herbivore and like Lystrosaurus they are able to feed on tougher plants like horsetails, giving them a massive edge in the harsh Early Triassic world. Another animal, is this Prolacerta, however, unlike the Lystrosaurus and Procolophon, it hunts other animals. The Prolacerta is attracted by the large amount of insects, for as the Lystrosaurus feed, they spook up a variety of insects. Prolacerta itself is a quick and nimble animal and it can easily run down most of the insects it preys upon.
At first glance Prolacerta looks almost like a lizard, however, it is part of a very different lineage and this can be best seen as it chases prey. The Prolacerta gets up on its hind legs to chase down a dragonfly even hopping into the air to snatch the bug right out of the air. Prolacerta can do this because its hind limbs are larger than its forelimbs and it is one of the first animals to exploit this form of locomotion albeit, Prolacerta is mainly a quadruped. Prolacerta itself is a member of the archosauromorphs, a family that includes crocodilians and of course its most famous members, the dinosaurs, many of whom will take bipedalism to the next level. Another feature of Prolacerta is its high metabolism, an odd feature amongst most reptiles and yet very common among the archosauromorphs.
In the future, relatives of Porlacerta will use these abilities to begin conquering the world, albeit Prolacerta's descendants will not be among these for they will soon fade away into extinction towards the end of the Early Triassic to be replaced by other more derived relatives. For now at least the Porlacerta can continue its daily activities unopposed.
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A few days later and the sun once again begins to creep over the horizon. As the new day begins to dawn, we find the Lystrosaurus drinking at one of the local watering holes. Water holes like this one are a beacon for life during harsh droughts and they attract all kinds of creatures. The Lystrosaurus are joined by the Thrinaxodon. The Thrinaxodon swiftly gulps down what it needs, for it would rather not be out in the open for too long lest it run into some of the bigger creatures out here.
Unfortunately for the Thrinaxodon one of the larger creatures is about to make itself known. A bellow from one of the Lystrosaurus, immediately puts the rest of the herd on edge. Making itself known is the Moschorhinus. Waterholes like these are often a beacon for not just prey but also predators, for on top of being a source of water, the waterholes are also a great source of food. The Thrinaxodon takes no chances and it immediately sneaks off, while it may not be prey for Moschorhinus, the larger predator will still often kill them to rid itself of a potential competitor.
The Lystrosaurus meanwhile shuffle nervously keeping a close watch on the Moschorhinus. The Moschorhinus for its part pays the Lystrosaurus no mind for it is still feeding on the kill it made a few days earlier, it is simply here to get something to drink. The Moschorhinus arrives at the water's edge as it begins to drink its fill. Afterwards the Moschorhinus heads off back to its burrow, leaving the Lystrosaurus to resume their activities.
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The Thrinaxodon quickly scampers back towards its burrow. As it enters the find the little Broomistega still present. Right now the little amphibian is sleeping. The Thrinaxodon pays the Broomistega no mind, as it lays down to rest as well.
A few more days pass and currently there is still no sign of rain in the sky. Despite this life goes on as normal. It is evening currently and we find the little Porlacerta on patrol for food. The Porlacertas high metabolism means that it must eat constantly in order to stay alive and as a result it spends most its day on the hunt. It suddenly stumbles upon a scorpion.
The arachnid throws up a threat display, lashing out with its large claws and deadly stinger. The Prolacerta must be cautious, the scorpions venom is potent enough to kill a small creature like it. It snaps at the scorpion, as the scorpion lashes out with its tail and claws. The Prolacerta suddenly grabs the stinging tail and snaps it off. Now the scorpion's best weapon has been taken from it.
The Prolacerta quickly pins the now mostly helpless arachnid as it begins to feed upon it. After eating the scorpion, the Prolacerta heads off ready to continue its day.
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Elsewhere, we find the Moschorhinus in the process of dragging a Lystrosaurus back to its burrow. The Moschorhinus likely made this kill just a few minutes ago and it is getting ready to feed upon it. A loud hiss suddenly catches the attention of the Moschorhinus as it turns to see a large reptile walking towards it. This is a male Proterosuchus fergusi, at 11 feet in length, it is the largest carnivore in this region. The Moschorhinus immediately growls at the Proterosuchus snarling as it puffs up, attempting to look bigger in an attempt to scare off the Proterosuchus.
The Proterosuchus is unfazed, as it simply continues walking right towards the Moschorhinus. The Moschorhinus, seeing that the Proterosuchus isn't backing down, decides to flee the scene. The Proterosuchus, having got what it wants, begins to feed on the kill. Proterosuchus is related to the earlier Archosaurus, however, on top of being slightly larger, its skull is also significantly bigger and more solidly built allowing it to tackle larger prey than its earlier relative. Proterosuchus itself only just appeared very recently in the past few thousand years and yet it has already begun to become the apex predator of this region.
The success of Proterosuchus signals the beginning of the rise of the archosauromorphs for as the Triassic continues on they will only continue to grow larger in size. Unfortunately for therocephalians like Moschorhinus, their rise coincides with their fall, while Moschorhinus survived the Great Dying its reign is a very short one and soon within the next few thousand years it will fade away into extinction. The Proterosuchus quickly begins to tear into the carcass, being big allows it to bully smaller predators like Moschorhinus off their kills and then they can then enjoy the spoils, this saves energy and is an effective way of getting food. The jaws of the Proterosuchus are filled with curved teeth with sharp serrated edges, making them great meat cutters, the Proterosuchus uses its jaws to rip chunks off the carcass, as it then gulps them down. The smell of the dead Lystrosaurus fills the air and this is a beacon for scavengers.
One of these scavengers, is the little Thrinaxodon. The Thrinaxodon watches the Proterosuchus intently, waiting for it to eat its fill so it can grab some food for itself. Finally after a short wait, the Proterosuchus wanders off having eaten all it can, the Thrinaxodon seizes the opportunity, as it runs towards the carcass,the Thrinaxodon then quickly begins to rip off chunks of flesh for consumption. The feeding of the Proterosuchus has left much of the carcass already torn open allowing the Thrinaxodon to access the best slices of meat more easily. It won't be long before it has eaten its fill as well.
It seems that even in this new world one thing that has not changed is cynodonts being scavengers feeding on the scraps left by the larger predators although of course now the apex predators have changed. After eating its fill, the Thrinaxodon scurries off heading back to its burrow. Sometime later, another smaller scavenger arrives to get its share. The little Prolacerta has once again grown hungry and luckily the Lystrosaurus has provided it plenty of food. The Prolacerta quickly feeds on the bits of meat left; its relatively slim teeth restrict it to parts where the larger animals have already eaten from.
Soon it too eats its fill and it then scurries off back into the brush. By the time all the carnivores are finished, there isn't much left of the carcass and the bones will likely bake under the scorching sun as the midday heat rolls in once again.
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Days continue to pass and there is still no sign of rain in the sky. Droughts like these can go on for much of the year during the worst years and they often push the local fauna to the brink, their if nothing else a reminder of the horrible devastation of the Great Dying. Under the shade of a conifer, the Proterosuchus hides out from the sun's rays. It also pants to relieve itself of excess heat and this feature will become a common way of cooling down in most future archosauromorphs. After a short time the sun begins to set in the sky and the Proterosuchus heads down to the local watering hole.
Already at the watering hole, are the ever present Lystrosaurus. The herd shifts nervously, while the Proterosuchus pays them no mind. The Proterosuchus begins to sip up water. The Lystrosaurus begin to calm down as they realize that the Proterosuchus is currently uninterested in them. While they are still a little on edge, they are able to focus on drinking up.
After a few minutes the Proterosuchus finishes drinking it's fill and it slinks off, back into the brush.
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Soon the sun begins to set completely in the sky. The Lystrosaurus slink back into their burrows for they have poor night vision and they would rather not be caught out in the open. Other creatures are more content to strike out. The Thrinaxodon emerges from its burrow, nervously scanning its surroundings, after seeing the coast is clear, it heads out into the night. Unlike the Lystrosaurus, Thrinaxodon have excellent night vision and they often head out in search of food. The Thrinaxodon searches around looking for possible food in the area.
After a short search, it finds a beetle. The Thrinaxodon snatches up the insect in its jaws. Thrinaxodon is not a picky eater and bugs are definitely on the menu. The Thrinaxodon continues to search through the underbrush, it must proceed with caution, however, for it is not the only one out on patrol, because of this, the Thrinaxodon makes sure not to wander too far from its burrow. Suddenly the Thrinaxodon hears something, its sensitive ears picking up the sounds of something bigger than it moving through the brush.
Immediately the Thrinaxodon freezes and crouches down low in the brush, its short legs means that it can't run very fast and so if caught out in the open by a predator, it would have very little chance of escape. Also moving through the brush is a young Proterosuchus. On top of being smaller than the adults, young Proteroscuhus also sport slimmer jaws and snouts giving them a less powerful bite, because of this they take up a different role in the ecosystem. This role includes hunting animals like Thrinaxodon. The Thrinaxodon can only hope for the best as the Proterosuchus walks on by.
If it is detected then it is doomed. Luckily for the Thrinaxodon, the Proterosuchus walks on by without noticing it. The Thrinaxodon waits for a minute and after scanning the area it bolts heading back for the safety of its burrow. It soon makes it back and we find the Broomistega still sleeping soundly inside. The Thrinaxodon soon joins it as it too lays down and begins to rest.
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A few days pass and the sun continues to beat down. We find the Lystrosaurus herd feeding on horsetails and joining them are some Procolophon. As the herd feeds, they fail to notice the adult Proterosuchus watching them. Today the Proterosuchus is hungry and Lystrosaurus are very much on the menu. The Proterosuchus silently moves in closer, hoping to catch the herd off guard.
Once it gets close enough it strikes, bursting from its cover and charging right towards its prey. The Lystrosaurus squeal in terror and bolt, as the Proterosuchus begins to chase them down. The Proterosuchus is quite fast in short bursts, however, it can't keep the pace up for very long, so closing the gap quickly is critical. It soon catches up to an old female who is slower than the rest of the herd and it grabs a hold of its back leg with its jaws. The Lystrosaurus squeals in terror and pain, as the Proterosuchus teeth slash into its leg, causing blood to flow from a now open wound.
The Lystrosaurus leg buckles, as it falls to the dirt. The Proterosuchus quickly goes for the throat and clamps down, its sharp teeth slicing up the blood vessels. The Lystrosaurus is dead just a few seconds later. The Proterosuchus then proceeds to slice into the carcass, feeding hungrily on it. Soon the powerful predator eats its fill, before heading off to rest.
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Later that day, as the sun begins to set and the evening begins to set in, we find another Proterosuchus as the local water hole getting something to drink. This particular Proterosuchus is an adult female. Being a female, she is slightly smaller than the males of her species, albeit she still greatly outsizes her other neighbours. As she begins to drink, a rumble catches her attention as she turns to see the male Proterosuchus walking towards her. Proterosuchus are fiercely territorial and the usual reaction to an intruder is to violently drive them off.
Rather than attack, however, the male instead lets out low vibrations, he is interested in making love not war today, for it is the breeding season for Proterosuchus and despite their solitary nature Proterosuchus males will often mate with the same females every year. The male lets out a few more gentle rumbles. The female seems receptive and the pair head off, they will remain together for the next few days and mate multiple times in that period, then the female will head off and wait for the arrival of the rains to lay her eggs.
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As the days tick by, there is still no sign of rain in the sky. The drought this year has dragged on for an unusually long period of time and this is thanks to bizarre changes to the normal weather patterns happening in the seas. These changes cause different impacts depending on the region, for example while South Africa is barely receiving any rain, elsewhere brutal storms ravage coastlines. The harsh conditions of the drought has begun to affect many animals here, some Lystrosaurus, especially young and elderly individuals are starting to die from the brutal conditions. Luckily many of the surviving Lystrosaurus begin to act quickly,as they den down to hibernate and wait out the rest of the drought.
As the herd heads into their burrows, they leave their dead companions to bake in the sun, for Lystrosaurus lack any real emotional bonds outside of mothers raising young and even there, the mothers will quickly forget about any fallen offspring. The recent deaths prove to be a windfall for scavengers. The Prolcaerta is quick to begin feeding on the softer parts of the carcass, albeit it can't penetrate the thicker parts of the Lystrosaurus restricting its feeding to certain locations. A hiss suddenly gets its attention, as it spots the juvenile Proterosuchus that our Thrinaxodon briefly ran into also coming to get a bite. The Prolacerta quickly bolts, for juvenile Proterosuchus will often snack on Prolacerta.
The juvenile is far more focused on the meal right in front of it, however. The juvenile quickly begins to feed on the carcass, tearing off chunks. If he survives to adulthood, he will become one of the fiercest predators on the planet, but surviving is the hard part. He quickly eats his fill before heading off to rest while his meal digests. The Prolacerta, having not gone far, seizes its chance as the Proterosuchus leaves the carcass.
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A few days later something begins to change in the air. In the thick of the night, dark clouds in the sky signal the arrival of rain, after months of drought they have arrived in force. This is no ordinary rain, however, it's a brutal tropical storm, one that dumps massive amounts of water upon the region. The massive amount of water causes dramatic flooding to strike the region as massive amounts of water fill lakes and rivers. The water soon flows past their banks, as the entire region is soaked.
Nestled within their burrows, many Lystrosaurus, having gone into hibernation towards the end of the drought, have no escape and many are subsequently drowned by the floodwaters. The rains last most of the night. Day break reveals the aftermath. The area is soaked, a sharp contrast to how it was just a day earlier. Many Lystrosaurus now lie entombed within their homes.
Some of the Lystrosaurus have survived, however, they have now been evicted from their homes. Luckily Lystrosaurus are competent diggers and they will create new burrows to replace the old ones.
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The Lystrosaurus are not the only casualties, at the Thrinaxodon burrow we find both the Thrinaxodon and the Broomistega have also drowned. Safe from scavengers, their bodies will be buried and stored away for millions of years to come.
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In spite of the devastation, the storm has brought new life to this area. Many plants begin to awaken from their dormant states ready to take advantage of the rains. Many of the rivers and lakes also spring forth with water once again. This is a windfall for the many thirsty animals who are quick to take advantage of this. Lystrosaurus for example gather in droves around the replenished water sources and they gulp it down.
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Elsewhere in a secluded clearing we find the female Proterosuchus having made a nest in the dirt. She watches the nest intently, for buried beneath the sand are up to 40 eggs. In about 2 months time these eggs will hatch and she will intently watch over the young for the 3 months of their lives. The young themselves will quickly grow in the meantime and after that 3 months they will have to survive on their own. For now the mother must stay vigilant for egg thieves are an ever present danger to the nest and she must be onguard if any of the young are to survive.
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Back in the open, we find the Lystrosaurus lounging around. As they do so, the Prolacerta chases insects that buzz around them. Nearby the male Proterosuchus rest in the shade of a conifer, content to get a good rest in. This is a typical Early Triassic scene and yet moments like this will only last for a brief time in the grand scale of our planet's history. The reign of Lystrosaurus in particular is a short one.
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By about 248 million years ago the genus would vanish without a trace, for the Triassic world is an ever changing one and it waits for no one. Other successful groups would also vanish at around the same time like Prolacerta and its kin. Even the mighty Proterosuchus is destined to fade away and be replaced by other more derived archosaurs. Yet one should not look at these creatures as failures, for without them life likely would've never recovered to what it would become later on in the Mesozoic era. As the Mesozoic goes on life will continue to expand and thrive and soon the next chapter of life's long story will begin and yet there is one more stop for us as we see who will live and who will die as the final part of this part of the story is told.
Trivia
This chapter, is based off of the Lystrosaurus assemblage zone in South Africa.
The Broomistega and Thrinaxodon denning together and later being killed during the storm, is based off of an incredibly preserved fossil showing a Thrinaxodon and a Broomistega nestled together, likely killed by a flood. Its a truly remarkable find and one I felt compelled to show off here.
I planned to have a chase scene with the young Proterosuchus hunting the Prolacerta, but this was cut for pacing reasons.
I depicted Proterosuchus as terrestrial here as the evidence seems to favor this interpretation imo at least. I also feel like this thematically works better which is a nice bonus as Proterosuchus shows a nice progression from Archosaurus, as well as being a better showcase for later Archosaurs imo at least.
A scene where the male Proterosuchus fights off another male of his species, was also cut and replaced by the scene where he courts the female.
Thats all for this chapter the next one will be the finale for this season as we move further into the Mesozoic and we shall see who is destined to inherit the planet.