Craterlands

295 Million Years Post-Establishment

Throughout the hothouse age heavy weathering of bedrock occurred across Serina from the constant rainfall, though the effects were often poorly visible as the eroded landscape simply filled with water and became lakes and ponds, leaving the landscape to appear flat. As the world cools and the plains dry in the start of the final stretch, sea levels fall quickly and with them so does the underground water table. As the central soglands drain and reveal their many entryways into te coalseams caves, a hilly landscape of many elevated plateaus and tables is revealed, interspersed with deep, wet craters that were once lakes that reached into underground caves. The floors of these low-lying craters are now the last hold-out for permanent wetlands and forest, now left isolated as low-elevation islands in a drier world in the newly-formed craterlands region. 

The largest of these regions is Sanctuary Crater, the remnant basin left behind by the Centralian Sea which has now almost completely evaporated and otherwise drained away into the crumbling limestone bedrock as the continent has dried out and much of Serina's water has now begun to evaporate out of the thinning atmosphere. The sudden and surely catastrophic loss of this greatest of lakes brought the end for many aquatic organisms, but has now also provided a new refuge for those of the land that will save them... for now.

The largest craters now create a protective bubble of milder climate: they are so large and so low that they become permanent high-pressure air systems so that dust storms from the flatlands beyond them almost never descend into them, instead going around. The atmosphere is thicker here than anywhere else, and it is still easy to breathe and easy to fly, while elsewhere conditions at sea level have become like those once only encountered in alpine regions. Freshwater in the crater valley is replenished through rivers that fall down the crater walls from the outlying lands as water travels to the lowest elevation. Even water that evaporates now rarely makes it past the crater walls, instead condensing into clouds before it ever escapes, to fall back down on the basin as frequent gentle rain showers. Temperatures are only mildly seasonal; summers are tropical, but winter may bring light snowfall which rarely accumulates. There is still no better place to live in the final stretch than there, and animals know it: all forms of life have traveled from across the continent to settle here and flee the harsh conditions from the outer world. But though the craterlands are a haven, living here does come at a cost. Animals which make their homes in the basin are no longer subject to the slow changes of the wider climate and cannot acclimatize gradually. When one day the craterlands no longer provide protection, when there won't be enough water or air pressure to maintain their stable climate, almost all who live here will be left with nowhere to go. Only those few species which remained on the high crater walls, still exposed to thinner air and less favorable weather, will stand a chance then. 

There is perhaps no better comparison of how differently the bottomlands of the crater versus the high walls influence the evolution of each animal which lives there than can be seen in the unicorns. The lowland unicorn is a member of the Retortunus genus which has adapted to live only in the low-lying grassland of the interior Sanctuary Crater. At nearly 300 pounds, it is a little over 5 feet high at the top of its much large, tightly spiraled horns, elaborately large and modified into dish-like structures at their tips which face in opposite ways. They are highly social, and live in herds led by single dominant males. The male truly is the patriarch in this species, unlike many earlier relatives in which females made decisions while males were peripheral protectors. He ultimately chooses when the herd will move and to where, though a dominant female, who is usually older and more experienced than him, frequently functions as his advisor.

Lowland unicorns are longer-legged and much faster runners on level ground than earlier cliff-climbing unicorns like their ancestor, the skyland unicorn, but this comes at the cost of being very poor climbers. Though if threatened they can quickly scale steep grassy hills, their hooves are much worse at finding purchase on sheer cliffs and their larger size prevents them from making long leaps; they have already lost most of their ability and all of their motivation to leave the crater, and have become all but spoiled on the lush green grass they find there and grow fat on. Their primary habitat is the flat, marshy plain at the bottom of the crater, close to drinking water, and away from the thick tree cover of the crater's edges which provides hiding places to predators. It is a grazer, contrasting browsing habits of most unicorns, and individual herds of ten to twenty animals sometimes congregate in the best feeding grounds in aggregations of thousands as the crater's most numerous thorngrazer species.

The call of the lowland unicorn is varied and resonant, but not very loud individually - they are always close together, and there is no need for long distance communication between individuals. It is though very complex and melodic, with varying tones and rising and falling pitch, and calling is often harmonized creating a beautiful if eerie melody which is much louder than any one's voice alone, and which allows different herds to hear each other from far away; there is some evidence that vibrations from these group-songs can carry as far away as neighboring craters, and may call unrelated unicorns in from other craters in to mate; this is the only time the species may sometimes still leave the craters, and it is mainly males which will travel so far. Females of this species have small intertwined crests, though only about 20% as large as the males', and can so produce a better variety of calls than the mostly silent females of the highland unicorn. Males have larger tusks - and a bigger head and thicker neck in general - than highland ones, and this reflects more frequent physical combat against other males over mating rights, since this species lives in large groups without defined territories and faces rivals far more frequently. These weapons are intended to slash the face of an opponent with sideways sweeping movements. The crushing jaws are also used in aggressive interactions, with some focus put to bite their rival's front legs - a way to produce a crippling injury, if either is not careful. 

Herd-leaders are good fathers, protecting all of their young from predators faithfully, but when a new leader takes over a herd his first task is to drive out any which are not related to him. If they are too young to flee and survive on their own, he grabs them by the back of the neck, lifts them off the ground, and brutally shakes them to death, usually by dislocating their skulls. Mothers do try to defend their offspring, as well as their familiar established male, and a herd with a strong lead female be able to coordinate their efforts to thwart a takeover and collectively keep the new male from taking control. In some instances, even with the death of their leader, an all-female group will defend itself from take-over by a new male until their young have all grown, and only then accept a new one, demonstrating that they are not entirely at the will of the opposite sex when circumstances are life or death for their young. Yet unlike many other herd animals - especially birds - lowland unicorn mothers don't care for any calves but their own, so that orphans are left behind, and their motivations to prevent the integration of a new male are entirely selfish. If a female loses her calf for any reason, or never had one, she will immediately seek out a new partner, apathetic to the safety of anyone's child but her own. But there is a cost to going against the needs of the majority: if she endangers other's young by luring in a male before they are independent, then they may cooperate to attack her, a harsh example of mob justice.  Even in some of the most socially complex thorngrazers, there remain harsh undertones to their behavior, which still follows a survival of the fittest mentality.

The sides of the craters, made up of steep sheer cliffs, comprise a habitat that was rare in the early hothouse, though appeared as sky islands evolved by 290 M.P.E. As sky islands are now rare and their remnants eroding away in the elements without their symbiotic ants to maintain them, the walls of the craters now provide a surrogate habitat, and a home to the highland unicorn - somewhat a misnomer, for the rocky landscapes it dwells on are now technically below the elevation of what was formerly sea level. Nonetheless, this small, sturdy crested thorngrazer which also descended from the skyland unicorn remains a very skilled climber, with thick, short legs and suction-cup like concave hooves on each foot, four in front and three in back that let it hold tight onto sheer surfaces on the edges of the craters, where it avoids terrestrial enemies not adapted to navigate such complex terrain. They have evolved even longer almost vertically orientated snouts and narrow cropping beaks that can fit between boulders to reach small patches of grass, and unlike many small crested thorngrazers they too retain tusks, but only two small ones on each side of the upper jaw and several small horns higher on the face, that males use to spar. This is the more primitive of these two unicorns, and represents the type of animal that the lowland form recently evolved from. Having remained at the fringes of the craterlands ecosystem, it has remained hardier to harsh conditions, and still very easily migrates from one crater to another, no stranger to heat, cold, aridity, and low-oxygen air.

Male highland unicorns have very unique crests, formed as they grow together in a tightly coiled formation and then widen into funnels, opening outwards in opposite directions at their distal edges, which serve like megaphones to amplify their vocalizations even more than other crested thorngrazers. Though only as big as a goat, the highland unicorn has the loudest call of any contemporary land animal, up to 150 decibels and enough to permanently damage the hearing of animals close by. The unicorn's call is so loud because unlike most of its relatives, it is a solitary animal - especially the male - and individuals may be widely separated in different craters miles apart. Males thus need to broadcast their presence over wide distances, and do so with incessant, painfully loud metallic clangs, often lasting up to 30 seconds, and sometimes repeated more than thirty times an hour as they move around the cliffs. These calls are so loud that they can be used as actively damaging defensive weapons against predators; as a result, male unicorns are rarely hunted except at night, when they rest. The sound begins at a pitch too low to audibly hear with a human ear but which can carry for up to ten miles in ideal conditions, then rises to a high pitched din that exceeds the high limit to human hearing. The craters themselves serve to strengthen the unrelenting calls even more, their shape crudely mirroring the funnels of the unicorn's own horns to carry its voice far and wide across the land. Calling reaches a pinnacle when a female is sighted, as the male becomes more excited and increases the calling frequency to two or three shorter bursts a minute.

Females, who don't need to be heard, only to listen, don't have any crests at all, but have large, mobile ears which can be opened and focused to the calls of distant males like radar dishes. Both sexes can seal their ears tightly both externally by folding the pinnae, and internally by compressing muscles inside the head to close the entire ear canals, preventing ear damage from their own calls and those of nearby males.

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The highland unicorn's high alpine habitat, in conjunction with its defensive calls, means it has only a single significant predator. One of the last repanthors, the gargoyle makes its home on the steep walls of the craterlands. Its habitat ranges from sheer cliff-faces to slopes with a mild enough grade that trees can grow in dense thickets upon them, still out of reach of many grazers. With immensely muscular forearms and strong grasping digits the gargoyle can clamber along the most precarious perches to stalk its highland unicorn prey, which is one of few large grazers that can access the plant life which colonizes the crater walls. Gargoyles spend their entire lives on the high walls, not entirely by their own choice; they excel at climbing the cliffs, but lose all advantage on level ground against other stronger predators that dominate the crater floor below, which will kill them if they catch them. They are forced into an existence at the fringes of the craterlands, caught forever between the productive green bottomlands and the hostile flatlands beyond their walls. Here they favor isolated forest pinnacles, growing on small ledges and plateaus on the crater walls. The trees and bushes provide hiding places, both to remain unseen by their prey that frequents these same high-elevation glades, and to remain undetected by rival predators that will steal their kills and threaten their vulnerable cubs. Shy and wary despite its fierce capabilities, gargoyles leave the shelter of forest pockets only under cover of darkness. Though males wander more to seek out mates, females may stick to surprisingly small territories, avoiding crossing gaps of open rock unless they have no other choice. 

The 150-220 lb gargoyle in its own element - hidden and creeping on the high forested cliffs - is the epitome of all a predator should be - powerful, athletic, and highly intelligent. It is built like a leopard mixed up with a chimpanzee; cat-like claws grow from the tips of its dexterous fingers, letting it hold tight onto prey with a grip few ever escape. Prey is taken by ambush, preferentially in its sleep, and this is the safest way to kill a large male unicorn whose sonic weapon can cause debilitating harm at close range. Female and juvenile unicorns will be targeted by day, and may be run down for a distance of several hundred meters. Both hunter and hunted race across the most difficult alpine terrain during such a chase and are equally matched in their skill. Successful catches result if it leapt on from behind and get its victim into a deadly embrace. It is restrained with the arms and then beaten forcefully against the rocks to subdue it, finally killed by a bite to the neck. 

The gargoyle has another trick up its sleeve too. It can take advantage of the sheer cliffs to kill unicorns with little work, if it can push them off the edge - but to do this requires a forceful shove, and it is all too easy for the hunter to tumble off after the hunted. Yet this repanthor has folds of skin along its arms which run back to its hind leg that, when it spreads its limbs, forms a parachute and slowing its descent. By angling itself just right, the gargoyle can simply aim itself back to the cliff and catch its fall before attaining a dangerous speed. It can then follow its kill down to where it falls and retrieve it. A gargoyle is tremendously strong, able to haul a carcass nearly its own size up almost vertical rocks to cache it out of reach of rival predators that patrol the crater floor. But it must quickly hide it in thick vegetation, out of sight, lest it still lose its had-earned prize to another hunter that is this predator's own arch enemy. 

While many hothouse scarreots could survive on a fully vegetarian diet, few species did so exclusively. This reluctance to specialize is now their saving grace. 

Grasslands still support some species of small scareakeets that feed on little seeds, but the forests of fruiting, nut-bearing trees that the largest scarreots co-evolved with have greatly reduced in spread with the sudden climactic changes that bring the end of the hothouse age. Were these birds inextricably tied to their food plants, then they would all face imminent extinction. But scarreots are generalists, and they are intelligent. Not all of them will make it - but the carnacaw, a descendant of the rascaw, has weathered severe changes to almost every aspect of its life remarkably well. By reverting to carnivorous behavior like the closely-related daggerbills, but combining behavioral flexibility with a less specialized beak, they now usurp them. A spearing beak is only useful to feed in one way, but a beak that can hook, cut, and crush all in one is like a swiss army knife, useful to gather any type of high-energy food that can be found in the new, drier climate. The carnacaw still feeds on plants - it eats anything it can get. But without many fruits or seeds big enough to sustain them alone, the carnacaw also hunts animals to survive, and gets its meat through many varied and sometimes morbid methods: to survive what is to come means the willingness to do whatever you can to get what you need, at the expense of anyone but your own. This simple truth has made the carnacaw a menace to all other animals that shelter in the refuge of the craterlands, almost all of which may find themselves on the receiving end of its appetite, and few which are able to defend themselves when they descend from the cliffs in their packs and choose you as their target.

Carnacaws are vicious birds, which survive in the face of difficult circumstances by fighting to the end and an enormous level of confidence that far exceeds their size. While they are a massive scarreot - the heaviest ever to live - with a body weight of up to 12 pounds and a 5-foot wingspan, they are still much, much smaller than many other predators of the craterlands. Yet they are powerful for their size, and know that numbers gives them an edge; they boldly confront larger hunters in gangs, and are able to quickly deliver debilitating bites in succession that can make even huge animals retreat, letting this devil parrot steal a larger kill. The jointed beak of the carnacaw has blade-like projections that meet when the distal tip of the beak folds back beneath the base of the beak, shearing meat like a set of scissors and letting the bird quickly fill its mouth, clean meat neatly from bone, and even cut off limbs of small animals and carry the whole cut of meat away to store for later. Packs of carnacaws will cooperatively chase and kill prey as large as thorngrazers on their own, even ambushing sleeping unicorns on the steep slopes in the night; unlike most birds, carnacaws have acute vision in both day and night conditions, and can be active at any time of day.  Even other carnivores aren't entirely safe; the carnacaw is the single greatest threat to young gargoyles, a fearsome cliff-dwelling species of repanthor.

Probably the most horrifying behavior demonstrated by the carnacaw, though, is its tendency to fly down and feed from megafauna down at the bottom of the crater, while they are very much alive and aware. Carnacaws in many of the craters have learned that it is easier to graze on the larger animals than try to kill a smaller animal outright. Flying out over the herds of unicorns or trunkos, they single out the weakest link and descend upon it to take bites from its back and hindquarters until it is literally eaten alive, piece by tiny piece, over the course of an entire day or more and gives up, resigning itself to its fate.

 The carnacaw isn't evil. It is just especially good at finding ways to survive, ways that appear abhorrent when viewed through the perspective of moral creatures, but are not exceptional in any way in the natural world in which death is as natural as life itself. Within its own clan, it is actually a very altruistic animal. Many carnacaws cooperate to rear the offspring of one to three dominant females, and even unrelated birds are allowed to integrate into these groups. Chicks are raised in deep cliff holes, dug out by many birds over tens of generations, and the larvae are hand-delivered choice tidbits of meat around the clock by a wide extended family of up to 50 adults. They pupate and are then gently moved to a second nearby den, so that they are not injured by the indiscriminate feeding of their still-growing younger siblings, and there they are watched over by other adults whose entire role in the clan is child-caring, and who are also fed by the hunting parties that regularly descend into the canyons to catch food. Many of these individuals are old, having earned their keep for years before and simply become too weak to help hunt; some, though, may be unable to hunt on their own due to congenital defects or injuries during pupating that mean they have never been able to leave the roost at all. So strong is the social bond within the clan, that even those who will never be able to help hunt or to leave the clan and breed will still be cared for from infancy and given alternate ways to help the group as a whole to survive. 

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Not all cliff-dwellers survive through ferocity - others rely on avoidance of danger, while feeding on isolated food sources most cannot reach. The wingsuiru is a large, herbivorous skungaru evolved from the kangglider, which has evolved extraordinary powers of camouflage and escape to avoid its enemies. It has adapted to parachute across steep cliffs of the craterlands to escape predators including the carnacaw, and to reach the most isolated outcrops with small clumps of plants that are out of reach of all other grazers - even the fleet-footed unicorn. Its hind legs have become smaller, and it spends most of its time crawling on steep cliffs with all four limbs, its forearms sporting heavy hooked talons to find purchase on the most precarious footholds as it hangs face-up and feeds on isolated clumps of grasses and herbs pulled from the slightest cracks with its long, flexible neck. When the time comes to find a new patch to feed, it turns over and simply lets itself fall, spreading arms and legs and unfolding a massive blanketing skin membrane, or patagium, that catches the air like a kite and lets it ride the currents of warm air that rise from the craters below by day so as to slow its descent extraordinarily, despite its size of over 90 lbs, which is distributed over a very long and lean frame. A fan of feather-like scutes at the tip of the tail serves as a rudder to steer this immense glider from one point to another, sometimes covering 4,000 feet to cross canyons if thermals are available, but most often making slow, circling flights back around to a lower point on the same cliff. The wingsuiru's extended skin patagia are supported by an elongated third digit and run from wrist to tip of tail and from wrist to the edge of the animal's jaw, along the whole length of their bodies. The hind legs however are still free of the wing membranes, letting it push itself off the edge with great force as well as to run and leap unencumbered. 

With its dorsal surface marked in an outline-hiding pattern of gray, green and black, the wingsuiru can virtually disappear against the cliff backdrop as it roosts and grazes, and so it hides from winged predators. Yet in flight it reveals an incredible underside painted in bright red, gold, and blue, including two great eye spots which when suddenly flashed at a potential predator serve as a startle display, catching it by surprise and momentarily tricking it into thinking the wingsuiru is an even larger predator, an effect which is furthered by a sudden loud rattling call it emits when under duress. The wingsuiru needs only a moment of surprise to escape, closing its wings and dropping into a spiraling free-fall off the edge of the cliff, only to open its wings and careen to safety and leave any pursuers flying past with too much momentum to stop their dive as quickly.

Wingsuiru are social flock animals, moving in groups of five to twenty across the cliffs. Females have a single chick which is carried on their back for over three months before it can confidently glide on its own, but still returns to her for protection and comfort for over a year. Chicks' markings blend into those of their mothers completely, and until adulthood their undersides are also mottled to hide them from all angles. If chased by a predator, females will drop their chicks onto the cliff and flee; the young instinctively cling to the surface and freeze. The enemy, distracted by the mother, rarely notices. With luck, the female returns to retrieve her infant when danger has passed. With less luck, the young may be left orphaned. It can feed itself from a young age, but lacks the reflexes of adults to quickly respond to danger, and may not be able to glide well if its patagia are underdeveloped. Such a lost chick can sometimes encourage another mother to adopt it by emitting a plaintive whining distress call, though this can also lure in predators. As wingsuiru chicks feed themselves and rely on adults only for protection - and perhaps transport to feeding sites, too - it may not be a severe detriment for an unrelated adult to adopt an orphan in this way, and it may even be beneficial to its own young if it does, making it less likely predators will catch their biological offspring with another hanging around instead.  

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Wide, expansive forests are growing scarce again across the world now, with the craterlands a remnant haven for now, though even here savannah is beginning to appear in the middle of the crater, separating forest islands. But some forest animals, adaptable and resilient, aren't going down with these slowly sinking ships. They're changing with the land, and adapting to the more open landscape. Contrasting the wingsuiru, we return to the crater floor to meet an herbivore that has almost lost its power of flight in favor of life on the open ground.

The carnacaw is assuredly the biggest and meanest, but it is not the last scarreot. And it can be argued that neither is it the weirdest. That title might be given instead to its relative the trowelfowl, a species that is in almost every respect an opposite of its contemporary counterpart and again shows how differently life at a low level shapes animals compared to those still living at higher elevations. Trowelfowl are ground-dwelling birds descended from the scourfowl that on average miss the mark to be the biggest scarreot by only about two pounds, weighing between 7 and 10 pounds. They, too, are gregarious. But they are not, for the most part, dangerous nor do they do much hunting. When the seeds dwindled away with the trees outside the craters, these scarreots turned their attention - and their great big beaks - to the ground, and learned to dig. They now feed mainly on buried roots and tubers, using their flexible mandible like a backhoe to scoop up beak-fulls of soil and to pulverize starchy plant foods that even most grazers miss just below the surface. This is supplemented lightly by whatever worms, grubs, and very occasionally, molodont pups or bird's eggs that they find while digging for other things. Seed, once the scarreot mainstay, is virtually absent from the diet now - the beak is simply too large to pick up small grass seed, and the nuts their ancestors evolved to eat are now rarely found in the short, swampy plains of the craters where they live. They take advantage of the lack of brush cover here to avoid ambush by land predators, and their mottled green back plumage to hide from flying threats; sharp wing claws, turned to spurs, are used mostly by the brighter yellow males to fight over females, but can also be used to punch predators.  Trowelfowl are now much better runners than flyers, with small, rounded wings only useful for brief, fast flight to escape predators for a short distance, though like most flickbills the juveniles are able to fly longer distances and disperse to new craters.

The trowelfowl lives in familial groups like the carnacaw, and is one of only a few scarreots to make dens beneath the ground in which their larvae are raised on the same mostly vegetable diet as their parents, which is high in energy but requires a lot more food, pound per pound, to equal the protein content of meat, meaning the larvae have huge appetites that can only be satiated by the diligent feeding and nurturing by many adults. The trowelfowl has another skill that helps it provide food for its babies, though - it can, to an extent, control its own food supply through a simple form of agriculture. As flocks of trowelfowl till up the soil and pull up the clustered bulbs of their most favored food, the sog onion (a flowering plant in the sunflower family that resembles an iris), they preferentially eat only the big ones, letting the smaller offshoots drop back into the dirt and then scratching soil back over them. This lets them grow again, in soil loosened and enriched by their manure, to be harvested again in a few months when the flock meanders back around to the same patch later, once it has recovered. By dividing up the roots of its food plants and replanting them, it keeps them growing more vigorously than if they were left to crowd themselves, and ultimately both the trowelfowl and the plants' benefit.

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Molmoons are a genus of large seedsnatcher molodonts, the descendants of the red molmo that once called the nightforest their home. Like trowelfowl, they too are now grassland-dwellers which evolved from arboreal species once endemic to forests. They followed the receding jungles down into these drained lake basins, but time has not left them unchanged. As the forests grew rarer, and they could no longer cross them without touching the ground, they grew bigger and sturdier to travel from one isolated patch to another over grassland and plains. Their social bonds grew tighter, for they could only count on each other as defense against the dangerous hunters that stalked the ground when a tree to rush up into for shelter was not available.

There are now several species of molmoons. Lowland molmoons are the most common. They live in cooperative groups of up to fifty in the damp centers of the craters, always near drinking water, and still within reach of tall trees that they still rely on to escape land-based predators. Their diet is very broad but dominated by plant foods; while their jaws remain weak for their size relative to most molodonts, their overall increase in body size negates this, and their most favored foods are the smaller seeds of grasses and low-growing bushes which they easily pulverize in their narrow jaws. Troops of lowland molmoons forage by picking through grass, shallow water, and soil with their dexterous fingers, rather than by putting their heads to the ground; this lets them remain vigilant for danger, and with many eyes in a group, few enemies can catch them by surprise. As they live in the most productive region of the crater, lowland molmoons are not highly territorial, and have weakly defined dominance hierarchies. Childcare is communal within a troop, though adults spend most of their time caring for young which are related to them through a sibling, parent, or child rather than unrelated young, and when a group becomes too large to easily remember who is related to who, it splits into smaller subgroups, mostly by family lines. Lowland molmoons still sleep in trees, and though they have become too large to rest in suspended nests, they retain a nesting instinct and collect grasses and soft branches to weave into a simple cushion on which to sleep each night, which is abandoned the next day, likely in order to reduce the proliferation of biting pests.

The molmoon is not the only crater species which has grown bigger than its ancestor as it established itself here. The jousting snort is a common trunko of Sanctuary Crater, and one which is not especially huge at a glance. At 6 feet high and weighing around 280 lbs, it is within the average size range for a wumpo, except that it isn't one, nor is it very closely related. No, this is one of the biggest snifflers to have ever walked on land, and it is one of the most herbivorous. Though still an omnivore, its day to day diet may be over 90% plant matter, mostly the shoots of soft forbs which grow near water, as well as their tubers. It does not heavily feed on grasses, except for their most tender new shoots and their seeds, on account of their being harder to chew and digest due to their silica deposits within every leaf and stem.

Jousting snorts are one of the most sexually dimorphic trunkos, with males twice the weight of females, completely different in color - bright orange-red and black, compared to the female's tawny spotted coat - and sporting a massively elongated lower mandible which arcs to one side in an asymmetrical fashion at maturity. This lower bill is used to wrestle other males over the right to breed in the autumn, and its tip hooks left in over 99% of individuals. Outliers with a right-pointing bill can't fit their beak together with most rivals, and mostly have poor success in combat, though some may learn to play dirty and use this to advantage by raking their opponent across the face with it. Successful males have full access rights to female flocks numbering from three to as many as fifteen, and will sire all offspring within it for that mating season. But males do not lead these herds, they only gain opportunity to stay with them for part of the year. After about three months, the males leave their company and return to a solitary lifestyle while the females brood their eggs; once they hatch in the spring, they will together rear their young with no help from the male.

Male jousting snorts are encumbered by their enlarged lower jaws, which make feeding complicated. While females - which have slender, matching upper and lower bills - can feed easily by probing the soil and pulling at leaves with their beaks, males rely heavily on their trunks to bring food into the mouth so it can be chewed at the base of the lower jaw where the small upper jaw can meet it. The need for dexterity has led to the development of paired "fingers" at the end of the trunk which help to grasp food and lift it to the mouth without dropping it, and while the male needs this more than the female, the trait is present in both sexes, though the female's trunks are shorter. The jousting snort represents the peak form in the evolutionary trend its lineage has experienced for the last twenty million years years or so in which the nostrils have steadily moved down the trunk's length. In this species and its near relatives the nasal passages have extended very far down the snout so that the nostrils have reached the very tip of the appendage, while the trunk has grown longer again than in their immediate ancestors, making this the among the most elephant-like of all trunkos in both appearance and in function.

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The craterlands are, in a way, like a series of islands in the landscape. And so as some smaller species like snorts can grow larger, already giant animals like gantuans become smaller due to comparatively less food. The silky cygnosaur is a relatively small gantuan descended from the draconic cygnosaur. One of only a few surviving cygnosaurs in the post-hothouse landscape, these animals can be found across a disjunct and fractured range in central Serinarcta. They are tolerant of cold temperatures, for their bodies are more densely feathered than was typical for adult cygnosaurs in the earlier climate; in this respect they are neotenous (retaining such juvenile traits as full-body plumage later into life), but only slightly, as adult males still develop bright green head feathers and large, ornately colored head crests. Yet though sturdy in cold, they are not tolerant of drought, which restricts them to regions that still support non-grass vegetation and all but excludes them from the flatlands. Silky cygnosaurs are most abundant in the craterlands, a habitat they share with several other gantuan species. Of them, this one is an outlier for its hardiness to changing climate and is the most mobile. Silky cygnosaurs can still travel up and out of craters, traveling along routes they've worn smooth into paths winding up the slopes over countless generations.  They move between crater refugia and outlying watercourses, especially in the summer, while usually moving to lower elevations to spend the winter, and giving birth to their small young there in spring before adults move out of the valleys again. Their mobility so far prevents their becoming marooned in any one remnant habitat; silky cygnosaurs are capable of long-distance migrations to find favorable pockets of land to support themselves. They are the most successful post-hothouse cygnosaur, and the one which will last the longest.

A mixed feeding omnivore, the silky cygnosaur's beak is designed to cut soft green shoots, not most grasses; it can browse, particularly in warmer summer months, but it can also lower its long neck into water and feed on aquatic plants and softer grasses which lack the high concentration of silica typical of flatlands foliage. Like virtually all cygnosaurs this one does not pass up easy animal protein, consuming many small invertebrates as it feeds in water and gobbling up birds' nests as it browses. Unlike its near relatives though, the silky cygnosaur is not highly aggressive - though it uses its size to usurp carrion from carnivores, it is unlikely to hunt healthy larger animals, as stealing from real predators is a much easier method to supplement its diet. Loosely social, female groups of two to six but rarely more are usually found in association with a single male which defends them from rival males; other males, both old and young, will lead solitary lives.

~~~

Closely related to the above and yet again hardly alike it, the tyrant cygnosaur is the largest gantuan alive and the second biggest ever to live after the blimp, which could not walk on land. It exceeds the earlier ridgeback cygnosaur in mass, even with a slightly lower height, on account of its extremely robust build and can weigh thirty tons. At this size the adult is very slow-moving and trapped in the lowest reaches of the crater, where it is confined to wetlands and the crater's central remnant lake. With few trees here to browse, it grazes, and its necks is permanently held horizontal, supported by a ligament that runs down its body all the way to its tail to reduce the strain on its muscles which also anchor on a large sail over its shoulders. It is a tremendously large animal, vastly larger than anything else that still walks the land, reaching such an enormous size only because it has outlasted all of the giant sawjaw predators that once hunted its earlier relatives and thus had nothing to fear when growing so large that its movement became limited and it could no longer avoid enemies. This animal is, in fact, another recent example of "island" gigantism; its ancestor, the fiendish cygnosaur, was one of the smallest and most nimble of the genus, and for that reason was able to outlast its former predators and find refuge here. Its increase in size has been rapid, too quick for its body to have time to properly adapt to bear its weight, and now it suffers for its size; as an adult, it is usually afflicted with chronic joint pain, and spends as much of its time as possible in deep water to relieve the pressure on its legs. Yet there is no pressure in natural selection to make it any smaller again, for it has found itself in an arms race with all others of its kind to be as big as possible in order to defend and secure a suitable feeding ground, which is accomplished through physical force. Even as its size becomes a hindrance, the tyrant is still growing bigger with each passing generation. This is an animal that is neither majestic nor beautiful. This is an animal for whom existence itself has become a burden.

Tyrant cygnosaurs, as their name suggests, are neither gentle nor polite. Their gigantic bodies need vast quantities of plants, mainly grasses, to stay alive, and they compete for this resource fiercely, always on edge, ready to throw hands with any other cygnosaur that challenges them. Fights are brutal and can be to the death, worst of all those between males, and each individual will play dirty in efforts to fatally wound its rival; there is no chivalry here. Huge necks crash together, beaks tear flesh, legs kick and spurs on hind feet slash, and tails strike and bruise and slice. Hard-wired to fight to survive and secure the extraordinary amount of food necessary just to exist in the limited habitat they cannot leave, their aggression extends not just to other tyrants but to anything they come across. Their worry about starvation blinds them so that they cannot afford to distinguish different kinds of animals. Only able to categorize "me" versus "them", it forms no bonds and knows nothing but enemies. These creatures are utterly intolerant of any perceived intruder on their territories, of any kind. This means that anything which comes too close and eats any of its own perceived food is a threat to its survival, and so it must be killed. The tyrant cygnosaur may be slow to walk, but it is far from harmless. Its neck can strike down or out to either side with unexpected swiftness, and the force of this impact alone can instantly kill most smaller animals if they're caught in its swing. Its range from behind is greater, as its muscular tail ends in a whip that strikes the air so fast as to break the sound barrier with a startling crack, just before it whips any intruder with so much force as to cut the smaller ones in half and lacerate the larger down to the bone. The extreme territoriality of the tyrant cygnosaur means that only small, fast animals can coexist with it, and anything larger than a few hundred pounds is relentlessly driven away, leaving the lake to appear almost vacant save for the small birds and aquatic creatures that can avoid the giant's ire by simply flying or diving away when approached. Unable to wander far from the support of the wet, and simply far too large to climb to any significant elevation, the tyrant cygnosaur maintains a dictator-like control of the small habitat it can reach, and shares it with no one.

Always hungry, the tyrant has lost any way to sense of when it is full, for in most conditions it must constantly graze to get the calories it needs to survive. But this also means that when it comes across a windfall of meat, a much richer source of energy, it gorges itself until it is distended and grossly bloated, and then still keeps eating. A cygnosaur killed in combat with another becomes a banquet to others all around that are drawn in to the irresistible scent of food. Only one feeds at a time, guarding the carcass from all comers, until at last it is so full it can do nothing more except retreat into the water to digest, sickened by its gluttony, and yet it would do it all over again the next day, unable to change its nature.

Its relative here in the crater, the small silky cygnosaur, has evolved away from the ornery nature of its precursors and flourished as a result, spreading across a wide range. The tyrant cygnosaur in contrast has seemingly doubled down on the worst aspects of its ancestors' behavior until it got itself caught up in a vicious cycle, where these traits now grow increasingly more extreme and exaggerated. Several factors seem to have made this inevitable; the sudden extinction of former predators, the restricted size of its suitable habitat, and also its life history: it still bears very large litters of young, but there are fewer predators to cull them now, and more of them than ever before reach adulthood so that they have no option except to face their elders in constant contests for limited space and resources. Only the biggest can win them, so the species continues to increase in size. One more secretive thing is also to blame: females of this species, like some Earth birds, can quietly influence the sex ratio of their litters through hormone concentrations shortly after conception, which will influence the sex determination of the embryos. Males are more aggressive than females, but are not likely to focus their aggression on those females if rival males are around. Maintaining a large buffer population of males to fight and ultimately kill off one another can make females' lives safer, so females may bear up to five of them for every single female offspring. This means that each female will have fewer same-sex rivals to compete with, and may escape the aggression of adult males until she, too, reaches adulthood. Female tyrant cygnosaurs are the only species where the female eventually grows bigger than the male, which she can only do because the females as a whole control the sex ratio so that males are always more common and so always engaged in conflict, leaving them with little time to harass them. Once fully mature, females can control the best feeding sites and keep males away from them entirely, further forcing them to fight one another for scraps on the boundaries of the wetland. When the time comes to mate, only the strongest will ever be considered, but she has to do little selection, for by excluding potential mates to the sidelines until they fight to the death, the fittest option will be the last one standing. And so having proven himself, he will sire the next generation of young, likely to be even larger and even meaner than the last.

~~~

The craterlands refugia provides a late-stage remnant of hothouse ecosystems, serving as a final home for many relic groups becoming rare if not already gone elsewhere in Serinarcta. Yet even here, in the final stretch, some new, distinct clades appear out of more generalized ancestors. The craterlands are now the home of the duckbucks, the latest new branch on the skuorc family tree, which has arisen only after the hothouse's end.

Duckbucks are several closely related species of crested, often decorated animals descended from the swamp skungaru. At home in the craters' wetlands, they probe into shallow water with wide flat bills and feed on water plants and crustaceans. Foraging with their heads in the water, they spend much of their time walking on all fours to splay their weight over a wider area and avoid sinking in mud, and their arms have lengthened to make this gait easier and more natural, though their hips still sit above the height of their shoulders. All four feet are webbed, and these are still excellent swimmers and capable divers, but they still spend much time on land and so retain feathered plumage except on their extremities. Indeed, though this species favors wet areas, in Sanctuary Crater it has adjusted to make more use of upland grasslands to avoid conflict with the tyrant cygnosaur.

The tail is short, paddle-like and very strong; it is used to propel them through water but also, in the male decorated duckbuck, to support a display structure held up by elongated spinal vertebrae. Males use this trait to attract a mate, and can flush blood into the skin here, raising a retractable fleshy membrane from the back up almost halfway along the length of the tallest spines. Both sexes have also developed far larger and elongated nostril crests; derived from bulbous, raised structures that let their ancestors breathe with most of the head hidden below water, they have now been repurposed as sound-amplifying chambers like the crests of unicorns. Both sexes produce very loud, reverberating calls to keep in contact with others of their species even across the width of the craters; males produce the most melodic, but also deepest and longest-traveling songs, advertising their fitness to females from far and wide. Much of the male's courtship call is infrasonic and so it is felt more than heard. 

While duckbucks are larger than their ancestors, they are only a little larger than cattle and are far from even the stunted craterland species of cygnosaurs. They are flightly and still quite fast, both on land and in water, and they flee from threats before ever considering to fight them. To move quickly over land, the duckbuck reverts to a bipedal gait and can still reach speeds of 35 miles per hour; this upright posture is also used when the animal is cornered and forced to defend itself, which it does with slashes of its forearm talons and kicks with its powerful back legs. Living in mixed herds of both sexes, duckbucks do not fight significantly, though males constantly display to each other to affirm dominance hierarchies, and only those highest ranking ones mate. Females give birth to two to four young once a year and keep them very close, cooperatively guarding their broods in creches up to a hundred young once they are a few weeks old; until that time, the younger ones are very often seen clinging safely to their mother's back. This communal childcare is beneficial for the survival of all young, as duckbucks have many enemies, and this way if a mother is killed while her chicks still need protection, they will remain under the watch of the other mothers as they are led around to forage in the swamps. Though a new lineage to the craterlands, duckbucks breed quickly and are very abundant; individual herds can swell to over two hundred thousand. Periodically populations may rise beyond the carrying capacity of isolated environments, and this forces large-scale dispersal events where herds migrate out of one crater and seek out another; this movement also allows new genes to enter insular populations. Still, during the most populous periods, many duckbucks may wander far from any habitable crater, to die en masse of exposure or starvation out on the flatlands. To the predators of that sparse region, it is a rare opportunity to feast.

~~~

The primary predator of the duckbuck, both in and out of the craters, is the herculena: massive gravedigger descended from the bristly hawkyena, which also hunts larger unicorns and young cygnosaurs. Despite its substantial size (over six feet tall and weighing up to 900 pounds) it is a gracile animal, with long legs, adapted to cover long distances and to actively chase down live prey. This is a widely-distributed carnivore, and an apex predator across its range through southern and central Serinarcta, where it favors the open grasslands that now one again dominate much of the continent. Gaining their name from their size and strength, even a single herculena can bring down prey twice its own body weight, and working as a pack these animals have few limits to their hunting success. Victims are pursued without rest for miles, run to exhaustion while the herculena is capable of remarkable feats of endurance. Nature is not always beautiful, and efficiency is not always a clean kill. Its food is often eaten alive, with the predatory animals biting savagely at the underbelly as the prey tires and slows down before ultimately collapsing, soon to die from shock. Diets are typically limited to slower, heavier animals - larger giraffowl, unicorns, wumpos, and surviving gantuans may all be taken. Most prey is social and travels in grazing herds which the herculena habitually follows, keeping their food always within a day's trek, and trailing them so as not to lose the opportunity in wide open lands where resources are now scarce and far between.

Adaptable to climate, the herculena can be found from close to the hot southern coast up to the tundra; populations differ in their patterns, from heavily spotted to dark to very pale, and in the extent of their plumage and range from thinly-feathered up to veritably shaggy. While females can remain in the pack of their birth throughout life if food allows it, they may disperse at maturity around the age of three in certain conditions or in certain populations. Males always disperse at this age and then travel widely; they can wander over a thousand miles before settling into another pack where they may reproduce. This dispersal provides gene flow across the population, even across the length of the continent, and has produced a highly varied, diverse species where genes that provide benefit in both hot and cold climates are carried by all individuals depending on the environment they live in Normally latent traits may suddenly express if they travel to a different climate from where they were born, with the density of the feathers being especially prone to change depending on temperature. Northern craterland herculenas are the most genetically isolated and may belong to a unique subspecies; they interbreed infrequently with other populations and are the most contrasted in color, with dark brown and gold feathers, large, dark spots, and a primarily white crest of quills on their rump used in social display to appear bigger to rivals. Here, in the vast valleys that were once ancient lakes, the herculenas are also smaller than others, perhaps because the temperatures here are less severe, while herds of smaller prey that may be inaccessible for outlying herculenas to catch can here by chased into the edges of the craters and so trapped and eaten. By switching the bulk of their diet here to these littler animals, they avoid competing as heavily with savage unicorns like corocottas and Diomede's mares that are their most major rivals. Craterland herculenas are still bigger than them, but are generally not as blindly aggressive. The more abundant resources of this biome, with more prey available in a concentrated area, mean that for most, a fight with such a hostile animal is usually something to be avoided. The corocotta and the mare are usually given a wide berth where they occurs, though the latter is notably absent from the largest crater. Herculenas here are more closely related to the largest and most aggressive steppe forms, rather than smaller forms of more northern craters.

Craters - excluding Sanctuary - are the only place where this species might consume a diet mainly of animals smaller than itself, and the place where packs are smallest, oftentimes comprised only of a mated pair and their young of two litters at most, one adolescent and one very young. Pups are dependent on their pack for two full years before being completely competent hunters, but even males will usually remain with their parents for three full years. Reproduction occurs less frequently than in many predators and is not usually an annual occasion. Two to four young are usually born in a den scraped out below ground or preferably within a pre-existing cave which lends shelter from the weather, only around every other year. By the time a second litter is born, the first are no longer strongly dependent and can contribute to the hunt. By the time a third is born, the oldest will have begun to disperse, leaving only females if any at all. In contrast, non-craterland populations usually retain all females born until the pack numbers fifteen or even more adults, the better to cooperatively take down larger prey animals than are usually bothered with by craterland packs. The larger group size of steppe populations may also serve to let them better compete against large corocotta clans; this second carnivorous unicorn is their primary rival for resources over their range and more than the mare is their arch enemy, for it is smarter and more cunning if not quite as fierce. Both species will kill the other if they can manage it with superior numbers, so it happens that both favor large group sizes to try and better their odds at winning confrontations. Yet the corocotta is capable of deceitful mimicry and is very skilled at splitting up groups of its enemies by imitating the cries of their young, invading rivals of their own species, or the alluring voice of a single female seeking a mate. This lets the corocotta single out lone herculenas and kill them as a mob, or to stealthily kill off whole nests of their young as the adults are distracted. For these reasons, the corocotta's range continues to expand, but that of the herculena now shows signs that it is contracting.

 Ecosystems are in rapid transformation now in the final stretch, and today's evolutionary winner can quickly find itself a loser when the rules to the game keep changing... the continued success of the herculena, for now, is ultimately uncertain.

~~~

Some herbivores are too agile and quick for the herculena to threaten. The satellope, descended from the side-striped signalope, is one of the most colorful herd animals of Sanctuary Crater, a nimble running molodont grazer as common in the bottomlands as on the grassy hills. More sexually dimorphic than its ancestor, male satellopes have evolved even larger, satellite-like ears as a display structure to court females, intimidate each other, and even scare off predators which threaten their herds. Both sexes still have a remarkable ability to adjust the markings in their ears, flashing colors like a cuttlefish by rapidly contracting and expanding chromatophores in different ways to express any conceivable color or pattern. 

But the males of this species have evolved a truly extraordinary canvas on which to illustrate their signals - their ears are now gigantic, stretching two feet above their heads when extended. Additional skin flaps unfold when the ear is fully unfurled, one dropping down on either side of the head, the other two rising upward and coming to a sharp point, further expanding the display. Instinctive communication signals are used by both sexes, and these mainly take the form of different flash sequences, often of black and yellow. Males get creative when trying to impress a mate however, and there is no set pattern used to get a female's attention - each male comes up with its own, often perfecting it over the first couple years of their life, but occasionally switching it up every few weeks. The goal is to really wow her, to stand out from the crowd. For some males, this means hypnotic pulsations of color, for others flashing bars, and many even produce huge eyespots and blink them - the latter is also used as a startle effect to frighten a predator, if the ears are suddenly flared from their compact folded position.

But there is something a little too real about the eyespots that most satellopes can learn to produce. They don't appear to be coincidentally designed, only resembling eyes by chance, like in most animals that have such markings. They typically have pupils which can move, eyelids which can angle and close, and even white reflections. The satellope is consciously mimicking an eye - and it can do more than that, too. The male satellope likely has the greatest control over its coloration of any land animal which has ever lived, even putting chameleons to shame. But their skills don't stop at flashing patterns and eye spots - some male signalopes appear to be able to "paint" a scene upon the inner surface of their ears, based on visual input from their eyes. It is usually imperfect, like a warped drawing, but so refined is the control over each pigment-containing cell in their skin that it is possible for some satellopes to slowly produce an image of another animal or a landscape upon their ears, as long as it is in front of them at the time. This suggests some sort of direct mental link between the input received by the eyes and the pigment cells in the ears, since the animal cannot actually see its own ears to know that it is accurately capturing said image or correct mistakes - it simply copies what it sees. The ability likely originated in males which sought to emulate the successful display patterns of other males which attracted mates, but is now transferred toward all sorts of other stimuli. Males can even memorize patterns in this way, and once it has made them once, it can instantly flash them again even months later.

As to what predator this strange creature fears, it is a fast and fierce one, and it is another molodont... a very distant cousin to itself. But while a small, fast satellope is always on its menu, it has one of the widest range of diet of any predator, and can even hunt prey too big even for a herculena thanks to its extraordinary capacity to alter its behavior when conditions require it, changing from territorial to cooperative, depending on environmental conditions. 

~~~

Sawjaws have declined in diversity after the hothouse age, with the largest species worst affected. Gantuan hunting subjugators are now extinct, their prey having experienced their own population collapses with the cooling and drying of the climate. As the world grows harsher, once again the smaller animals inherit what remains.

The magnificent manticore is a more fortunate survivor. Descended from the elegant manticore of Serinarcta's savannahs, it fed on the cursorial thorngrazers and upon trunkos - smaller prey which can still find enough food to survive. It has since followed them down into the refuges which remain as the surrounding plains turn to a dry scrubland. This sawjaw, though a far cry from its extinct relatives in size, nonetheless excels in hunting thanks to its high intelligence, social cooperation, and great agility, and combines the best traits of hothouse sawjaws both large and small to feed on a very wide range of prey. Magnificent manticores, named for the long mane, flashy red face, and white markings of the male, can adapt their behavior to take advantage of food ranging from small poppits to the satellope and rarely to even larger prey.

This species is noteworthy for its complex social behavior. Though the base of its social structure is a male-dominated harem of females and their young, for which males compete against each other, they are less aggressive than their predecessor - as in unrelated tribbetheres of earlier times such as the crested thorngrazers and the woodcrafter, the evolution of brighter markings has gone along with this reduction of aggression as display replaces physical fight.  For the magnificent manticore this is necessary because sometimes it is needed for many clans, normally adversarial, to come together toward a common goal, and it would not be possible if the males simply killed one another. This is what is occasionally orchestrated to kill a most unexpected victim: the tyrant cygnosaur.

Much of the time the crater is green and verdant throughout. Woodlands grow along the steep edges, safer from grazers, while plains dominate the sloping interior, with wetland at the center surrounding the lake. Then, it is unnecessary to hunt the hugest cygnosaurs - smaller prey abounds and is relatively easily captured in the grasslands. In this habitat of open, short vegetation these manticores excel, swiftly pursuing their prey and turning on a dime to follow it through the most desperate evasive maneuvers. But occasionally, normally as a result of semi-regular oceanic current disruptions, drought reaches even the crater. The herds of prey migrate - some like silky cygnosaurs and duckbucks may leave the crater entirely, seeking greener pastures in smaller basins around this largest, where conditions may differ. Others like lowland unicorns disperse into solitary bands, making it harder to track them. But the largest cygnosaurs will never leave - they no longer can, and they can only retreat further toward the center of the crater, where they must hope it remains damp enough to feed them, but where they are pressed closer together than at any other time, with less food, leading to the most severe fighting of any time where many will be left badly wounded. Normally, the tyrant cygnosaurs' extreme size protects them from even the largest typical clans of manticores. But if all of the manticores work together against a common target during their hardest time, even these giants may fall.

When their usual food is scarce, manticores that usually live in small close-knit groups form super-clans which can number up to 150, and rarely even more. Females are not receptive to mate unless food has been regularly abundant, and so during these times clan leaders don't usually need to worry about other males mating with their partners. Territorial boundaries temporarily break down, and the clans take on a roaming behavior which brings them closely together as they move toward the center of the crater. There they coordinate their behavior together as a single massive unit to target the giant skuorcs. They focus their attention on the weakest links - inevitably, males already wounded and weakened in combat with other males, forced to the periphery of suitable habitat and away from the safety of the water. They then mob the giant, an overwhelming number of enemies to focus upon, and as some distract it from left, right, and behind, eventually others are able to leap up onto the neck and head and start biting and clawing. The cygnosaur swings them around in furious battle, and even ailing and weakened and vastly outnumbered by its small assailants, it can still emerge victorious. But other times, after a contest which can last days, the beast at last succumbs.

With a tremendous crash, its body falls. There will, inevitably, be losses on the winning side in such an outcome too - but for the survivors, a single kill may well sustain them all until the crater returns to full vitality and the grazers return to the higher hills. They swarm it like ants on a fallen sandwich for weeks, and their predation of such a beast makes them part of one of the most imbalanced size ratios of predator to prey in any food chain. Then the clans can return home, their alliance having served its purpose. Weeks of gorging can bring the females back into breeding condition, and with a little luck they can time the birth of a new generation of cubs to just as the grazers return and give birth themselves. The males thus become rivals again, keeping their clans separate. But these elegant hunters don't forget those who helped them in seasons past, and if conditions deteriorate again, even years later, clans which cooperated in the past are the first to rejoin and work together again, and each time they do so, they form a more efficient team. Whether any true "friendships" are formed in this way over time, or whether it is truly just an alliance of convenience, is up to debate. What is certain is that this remarkable behavioral plasticity gives this sawjaw a major edge at survival in unpredictable conditions, at a time when few other sawjaws are still doing so well.

~~~

Sanctuary crater is a refuge, but as we've seen here, it is not a paradise.

Where prey seeks shelter, predators always follow behind. There are few animals with no enemies at all, and for those with few like the tyrant cygnosaur, they can become their own worst nightmare. 

Titanic toothtoads are monstrous descendants of the belligerent toothtoad, and among the largest ever lumpuses, weighing up to 250 pounds. Though their ancestor was sexually dimorphic, with a small, highly mobile male, this massive descendant is very similar between the sexes. There are few other suitable places around to migrate to, so neither sex needs to be able to move long distances. Both male and female are now huge, robust ambush carnivores with an extremely sedentary lifestyle. These animals can spend years in an area of a few square meters if food is available, and if they can acquire a big enough meal, they need to feed only once a year. They dug out a deep burrow into damp, preferentially clay soil nearby permanent water sources, ideally in a place with large trees with sturdy roots, or buried stones, on which the toothtoad grasps with its muscular tail and hooked claws. It then sits at the entrance of its tunnel, completely filling the space by flattening out its body, and leaving only the top of its head lightly exposed under a cover of sand; even this is often hidden completely. It doesn't need to see its prey to catch it - it's all about the vibrations that it produces with each step. With its whole body submerged in the dirt, the titanic toothtoad picks up every subtle movement of animals nearby. And it waits, for weeks or months, until something happens to walk just a little bit too close. And then it strikes.

This lumpus is a living bear trap, and its targets are anything that steps too close. It closes a mouth almost 30 inches across on the leg of whatever happens to have stumbled on top of its ambush, and once its jaws shut, they lock into place and will not be pried open even in death. It's maximum of 2,500 pounds of pressure per square inch is not anywhere near the limits of animal bite force - but its mouth is so wide that this is effectively impossible for its prey to escape from. It is not an indiscriminate biter - it can tell when something is too big for it - an adult gantuan, perhaps - and it will ignore it. Likewise, it isn't worth the toothtoad's effort to emerge from its burrow for a bite-sized animal, and so too will small animals be left alone. But when the prey is just right - something anywhere between its own size and around three times larger - it goes for the kill. A unicorn or a trunko finds itself instantly stuck, dozens of four-inch long, serrated teeth cutting deep into its leg. Once caught, the animal thrashes and does all it can to break free, but this is usually futile. The titanic toothtoad's body is well-protected from kicks and stomps, with plates of bone just below its thick skin that protect its organs from injury as its victims struggle. As soon as it grabs hold, it begins to pull itself back down into its burrow, dragging its prey kicking and screaming along. If the prey is small enough, it is taken underground and then, in the confined space, the toothtoad adjusts its bite to close on the head, and it gets a relatively faster death. Often, though, the captured creature is too large for more than its snagged leg to fit down the hole. No worry for the toothtoad, though. It will just keep pulling, its teeth digging deeper and deeper, until its mouthful is pulled away from the rest of the animal. The majority of its prey is bipedal or tripedal - in either case, it won't get far missing a limb. Such an animal might be freed, but it is doomed to die shortly of shock and blood loss, and will be unable to get far from its attacker before it does. Slowly, leisurely, the lumpus follows it out of its burrow, moving with an unhurried, plodding gait. It approaches its prey again, this time by another limb. And even more slowly, it returns it to the burrow, tugging until it eventually takes the entire carcass below ground. It is persistent and patient - it may take several tries to eventually pull apart its meal into enough small portions to fit the entire animal below ground. If they are lucky, death comes to them far sooner than it takes to complete the task.

Titanic tooth toads's equal sizes mean that mating is no longer very dangerous for the male, and these animals have lost the long, feeler-like ear tips used by the male to gently test the intentions of his mate at a distance. He no longer has to be so careful as he approaches the female's burrow, for she cannot really harm him - the skull is extraordinarily thick and resistant not only to stomping prey animals, but also to the exact sort of crushing she could do to him. So, by dark of night, the large males catch scent of chemical cues emitted by females that are ready to mate, and exit their own tunnels and go seek them out - a slow process. If they are at all receptive, they will come to the edge of their burrow and examine him when he arrives. But she will not accept a single male. She will wait until at least one other arrives, too, for she wants only the strongest one. The males are very territorial; they hiss and roar, snap their jaws, and if they are evenly sized, they will fight, sumo-style, one trying to overturn the other. The female will mate with the winner, impressed by his strength, but their relationship too is brief, and she will just as soon chase him off, snapping at his backside. A few months later, she will give birth to a litter of as many as twenty live young, each weighing about one pound. Unlike their parents, these are thin and able to scurry at some speed to cover, resembling the male of their ancestor species. They flee their mother immediately and scatter across the grassland. A very small percentage will settle down and reach maturity, a process that will take them up to fifty years. Most will be eaten by something else far before then, and all the better. Adults which make it can live for nearly two centuries, thanks to their very slow metabolic rate, and so the turnover rate in the population is very slow indeed. There is limited food in even this largest crater, and so reproduction is both slow - only one litter every few years - and done with the intent that only a tiny fraction of young need to survive to maintain the population.

~~~

From the "bear trap" to a "bear" itself, we come to the shovelbilled snagglejaw, one of the last few descendants of the fishing triyenas, and one of three to persist to 295 million years PE, all of them snagglejaws. Its survival has been secured, so far at least, by its widely divergent diet from all of its ancestors and close relatives. Unlike other triyenas, the shovelbill is an herbivore, up to 90% of its diet comprised of grasses which it grazes in the heartland of Sanctuary crater, its entire range restricted to this one low-lying refuge, where they are usually found in tall grassland growing near or in shallow water. The jaws of the shovelbilled snagglejaw are much blunter than their ancestor, the lesser snagglejaw, and are flattened much like a duck's bill. The cheek teeth are now flat and adapted to chew coarse food while those in the front of the mouth, particularly the lower jaw, are broad and angle forward, adapted to shovel vegetation up from the soil, roots and all, for consumption. These animals consume a lot of soil as they graze, causing significant tooth wear, so that all of the cheek teeth are replaced at least once annually. The lower incisors though, uniquely among foxtrotters, grow indefinitely to compensate for taking the brunt of the heaviest wear, and so remain in place throughout life. This snagglejaw's transition from carnivore to herbivore is an example of convergent evolution with the unrelated Serinaustran manducus and its descendants - both lineages are large, robust predators which adapted to feed mainly on grasses as a result of changing climate conditions reducing the availability of animal prey.

The vegetarian diet of the shovelbill, even supplemented as it is occasionally with small animals, especially fish, allows for a much larger population of animals to live in a small range than was possible for more predatory ancestors, and this is reflected in their social behavior. Shovelbilled snagglejaws are the most gregarious of any triyena species which has thus lived. Their clan structure is now loose but still segregated by sex, with females gathering in herds of up to several hundred on good feeding grounds, sometimes breaking up into smaller clans of five to fifty. Social bonds are weak in the female now, and though within larger herds smaller groups may remain together which are closer related, often animals don't associate closely with relatives once they are adult. Females are larger than males by up to 40%, reaching weights of up to 600 lbs. Males in turn are slightly more colorful, with brighter blue, green and sometimes yellow faces. Male social groups are smaller and closer than those of the female, consisting of ten to thirty animals which remain together and do not associate closely with other male groups. Adolescent males are driven out of their mother's herd around two years of age and spend some time alone, before integrating into a bachelor group in which there is a significantly higher chance it has several close genetic relatives than not; this assortative gathering can only be explained by an ability in this species to detect close relatives by scent or other cues, as such animals will not have grown up together, and males take no part in child care. Most males within a clan will be related to some degree, while female groups usually will not. Females can also recognize genetic closeness by scent, however, and reject related males even if they have never met them. Male groups periodically visit female herds and advertise their willingness to breed, seeking to mate with any females which may be in estrus. Though the male is somewhat brighter than the female, visual cues are only a small part of courtship, and females are most strongly attracted to very different scents than their own - they are likely directly comparing the genetic diversity of potential partners, as unrelated males will produce stronger and fitter offspring. Because every female in a group is relatively unrelated to another, each one has a different ideal they seek in a mate, which means no one male can dominate, and every one has an equal chance of being chosen to father offspring.

The shovebill snagglejaw is an unusual animal for being a plant-eating representative of a carnivorous lineage. As such, these animals remain large, relatively aggressive and well-defended against other predators, but even they fall prey to the toothtoad which lies in wait and is all but impossible to dislodge. And their young are mostly helpless in their first few months, and predation from fast and agile manticores is especially significant - less than 10% of young survive to a year of age, even though their mothers try to defend them. Survival rates may be so low because females don't typically protect young other than their own, and yet this may have been selected for because if more young survived to adulthood, the population of these large herbivores would quickly exceed the carrying capacity of their small, restricted habitat. The limited ability of Sanctuary Crater to support a population of such animals may be indirectly leading the species to become less intelligent and less cooperative, slowly transforming a lineage of once complex carnivores into something more like herds of cattle, and demonstrating once again that higher intelligence and social complexity is not always beneficial to survival in this ever changing world.

~~~

Back up on the cliffs, other animals have been reshaped by their new habitats. The slinking crink is a specialized descendant of the castacrane found only in the craterlands, specifically on their steep outlying walls, where they spend the days quietly roosting inside narrow stone cracks and spaces beneath boulders, where spiny back plumage and a short hooked spur on their ankle hold them in place. Though small, weighing about six pounds and being only around 14 inches long when at rest, the crink has a startlingly long reach when fully extended. It is a nocturnal predator, emerging from its tight quarters at nightfall to hunt small creatures that scurry along the crater walls by striking at them from a distance. It does so with an extensible neck which fully doubles its length. Really, the neck is fold-able, not extensible - at rest, it is tightly curled and tucked in front of the body, its outline hidden by the body feathers.

Two tentacles on the crink's face, those on its left and right, are also modified as prey-capture appendages. Circular rings of muscle support them, which actually do extend, being held in a contracted state when at rest. When striking prey, these rings rapidly release stored energy and extend the tentacle twice its length in a brief, elastic movement that lets it grab its target between the two barbed tips of the tentacles, which then automatically draw back in to their contracted position, pulling the morsel towards the upper and lower appendages, that in turn transfer it to the beak. When both its neck and its paired feeding tentacles are fully outstretched, the slinking crink is more than three times as long as when at rest, reaching up to 45 inches in length.

The crink has evolved rapidly from its ancestor species, perhaps because it was better-adapted to fill a novel sort of niche on Serinarcta not yet filled. Though the northern continent had many tentacle birds, all until now were trunkos, which lack an inherent extensibility to their trunks, and this has contributed to their being much more often herbivores than predators, and ambush predators virtually never at all. While it appears very different from other scroungers, the slinking crink actuality only exhibits exaggerations of traits already present in its precursors. All natatory scroungers have slightly extensible tentacles, which evolved to catch fast-moving fish; they are ancestrally predatory, unlike trunkos. All scroungers in general also have the capacity to have long necks, with the ability of most birds to acquire more in common, harmless genetic mutations, in contrast to the more constrained vertebrae seen in tribbetheres. In truth, the most novel trait acquired by the crink is not on its neck or head at all, but its opposable first toe, which evolved to aid in climbing up the edges of sky islands, and later down the walls of the craters, in order to find a safe roost to avoid their own enemies, and then to pursue prey in small hiding places. Though not closely related, this is a convergently evolved adaptation to the scansorial scroungers such as the kaks.

~~~

The crink has good reason to hide in the rocks, for the same cliffs it dwells in are the daytime gathering site of the shadowswallower, a predatory seraph that specializes in gobbling up other birds and even smaller thorngrazers. Though it is quite big, standing up to nine feet high, by the standards set by earlier aukvultures - themselves not too distant relatives of its lineage - it is only a middle weight. It lacks the serrated pseudotooth bills of the aukvultures, having only a small hook at the tip of its jaw. These birds spend most of their time high on the crater walls, where they roost in small groups, resting and quietly chattering amongst themselves. Their plumage is nearly jet black, save for lighter feathers on the face and a reddish tint to the wings in sunlight. Long of bill and of neck, when at rest they have a fairly ordinary shape, and though they might appear a very real threat to small animals, they seem skittish and hardly a threat to anything larger.

But everything changes when the sun sets and darkness washes over the valley. The flocks begin to stir, to stand on their hind legs and stretch their wings. Kept partly hidden, folded beneath their covert feathers, their full wingspan extends to fifteen feet or more. And one by one, in the shadow veil of the night, when even starlight is often hidden by the high walls of the crater, the swallowers drop from their clifftop roosts on those wide wings, and make a quiet descent down the cliffs.

They fly low over the ground, scanning it for movement. One approaches a large herd of lowland unicorns meandering toward a grassy plain toward a watering hole. They are sizeable animals, each weighing around three hundred pounds. A hunter without powerful crushing jaws or teeth to shred meat with, the gracile shadowswallower seems to pose little threat to them. But the shadowswallower is named that for good reason. A descendant of the passager hellican, they have an astonishing ability to consume their food, and without chewing it at all. The bird descends to just feet above the ground and falls into a glide directly toward the herd. Its flight is silent, like an owl's, with its wing feathers quieted by a comb-like structure at their leading edge that splits the air and quiets its movement. The adults, still unaware of its approach, aren't its target - they're too big. But the calves are just the right size. At the last possible moment, it expands an astonishingly large throat pouch with air, a sac running nearly to its groin, and stretching to over 3.5 feet in diameter. The shadowswallower instantly engulfs an unassuming calf weighing over 100 lbs from behind and comes to settle on the ground. As the rest of the herd bolts for cover from a threat they never saw coming, the swallower now expels all of the air from its pouch, and over the course of a minute or two, its trapped victim's struggles fall weak and then silent. Nearly doubling its own body weight, this bird can no longer fly once its pouch is filled, but it can still move quickly over the ground, and it returns toward the cliffs, where it will make some effort to ascend above the ground to a safe ledge without the use of its wings. A meal as large as this will provide for it for as long as two weeks. It takes as long as two days to totally swallow its catch, and it will hold it midway down its throat as part is digested away before swallowing it a little further. In an emergency, the shadowswallower will regurgitate whatever remains of its catch, even wholly undigested, and so regain the power of flight if it is needed to escape some larger and fiercer enemy - this is sometimes exploited by the carnacaw, all too eager to eat whatever it leaves behind, though it must be careful, as it too can fall prey to this hunter's bottomless maw when caught unawares. 

~~~

The vulperaptor, too, hunts the crater walls, though its prey is much smaller, for it too is only a little animal, though among its cousins, it's enormous. This is a carnivorous flutterfox native to much of Serinarcta, and at over 2.5 feet tall and weighing more than 30 pounds, it is among the biggest of these winged tribbetheres, and one of a handful of species which have been experimenting in losing their power of flight for lack of need after their ancestors reached the northern continent within the last five million years. Vulperaptors dwell on cliff habitats, and prey on small birds and other vertebrates that also make their homes there in the crevices of the sky islands and ledges on the rim of the craterlands. With very large wing claws, they clamber over steep, vertical rock faces and use their large hind leg to spring from narrow perches. A narrow ridge of muscle on their backs, or what appears to be their rump due to their monopedal posture, is lined with a fan of heavy interconnected bristles, and serves as a small tail to further balance their leaps. They seek to always approach their prey from above, so that they can then spread their wings and glide down atop it, snatching it in their jaws and shaking it quickly to dislocate its neck before swallowing it mostly whole. Mostly hunting at dawn and dusk, they are adaptable and can be seen hunting at nearly any of time of day if prey is available.

Vulperaptors are solitary hunters, but not solitary animals. Adults form monogamous pairs, and the loud, dog-like barking of these animals as each pair claims control over its territory against other pairs across the cliffs is a common sound that echoes through the craters just after sunset. Females do most direct childcare, but males provide food to their single young, which usually cling to their mother, even when she is hunting. Adult vulperaptors are surprisingly mobile and athletic even on flat ground, bounding on their hind legs and fluttering their wing fingers for balance, and can traverse wide areas between suitable cliff-side hunting grounds. Juveniles are even better dispersals, however, for they are capable of powered flight for around a year before they outgrow their wings and are then limited only to downward glides. This has allowed the vulperaptor to colonize a wide range of isolated high-elevation habitat across Serinarcta, and to reach several small islands newly formed off the coast of the continent by falling sea levels, on which they have few competitors and have already begun to reach sizes up to 30% larger than on the continent. 

With so many predators along the cliff walls, most smaller creatures are shy and wary. But one is an outlier, so much so that at times, it will even approach larger carnivores that could so easily kill it. And yet, they almost never do so. The cleaner sniffler is, at 2 ounces and a body length of just 3.5 inches, perhaps the smallest trunko ever to live. Related to the seaskipper, it shares a common origin, but is not a direct descendant. Like it, its ancestors evolved to opportunistically pick through the feathers of larger birds on the wetlands they evolved upon, fulfilling a beneficial cleaning service in exchange for being able to eat the arthropod parasites they removed. Like seaskippers, these small trunkos would also occasionally be carried away by larger birds in flight, grabbing hold of their feathers with their long toes and their trunks. Now they are obligate cleaners, and not associated with water at all. Having evolved flashy bright colors as an advertisement of their services and a bristle-tipped trunk that resembles a fine-tooth comb, the cleaner sniffler is now a denizen of the sanctuary craters of the craterlands, having been carried here by migratory birds within the last five million years as the landscape beyond them began to dry up.

These tiny trunkos live in gregarious groups along the cliff walls of the craters, near open grassy areas in a sunny location. They roost deep in the cracks they find there, which give them a safe escape from predators while also letting them emerge and put on a show to attract clients for cleaning. Their red plumage is marked with three lengthwise stripes that run from their head to their rump, where six wire-like white plumes extend outward. In sunlight the cleaner sniffler lights up like a beacon unmistakable, and as many as twenty of these birds cooperatively strut along the vertical rocks of the cliff, clinging with their long toes and raising their rumps in the air and twitching their tailfeathers, advertising their services to animals all around. All manner of birds and thorngrazers visit these stations, allowing the birds to climb up their bodies and to scurry through their pelage, combing out mites, lice and other blood-suckers. No large predator eats these snifflers; rather, fierce animals even open their jaws and allow them to venture inside and pick out scraps from between their teeth without fear. Smaller carnivores will occasionally hunt them, though only if quite pressed for food, but the sniffler's main threats are simply the weather; at such a small scale, even gentle wind and rain can knock it off the cliffs, and it is for this reason that the sniffler sticks close by its hiding places. When the weather turns anything but clear, they vanish into the rockwork, and their plumage so visible in bright light appears black and nearly invisible in deep shadow, further broken up by their white bands.

Despite its size, the cleaner sniffler is extremely intelligent. It makes its living reading the intentions of dozens of other animal species to determine who is friend and who is foe, and this all requires a very large brain, one of the the largest relative to its body weight of any bird, living or extant. Cooperative, mutually-beneficial interactions are the pillar of this sniffler's survival, not just to fill its belly. Cleaner snifflers also rely on large flying birds, and sometimes terrestrial megafauna, to transport young adults to new territories both within and beyond the walls of a single crater. They don't trust just any animal with this role, for it is a very vulnerable time for the sniffler to be away from the shelter of the cliffs, and only individuals they and their parents have interacted with most and come to know best will be trusted to carry them. 

As our journey through the craterlands comes to a close, and we ascend back up the crater walls and toward our next adventure, we come to where a male highland unicorn surveys its territory high on the rim of the Sanctuary Crater, the emptied sea now keeping a little bit of the hothouse world alive, as it enlists the services of a flock of cleaner snifflers resident in a hollow log nearby to remove pests from its fur coat. The valley that it overlooks as they pick through its hair, removing its parasite and gaining a meal in return, is now the lowest elevation in the world. After continued erosion and collapse of the lake's floor, its walls rise a mile and a half, while the lowest floor at its center now sits almost three miles below the former level at the shore of that lake. It's one of few places still wet enough for the grass to grow lush, and for green trees and colorful flowers to blanket the steep hills around it, almost all year long. When the sun crests over the edges of the bowl in the morning, a rolling fog quickly dissipates and the skies clear. It is a beautiful place, and in many ways, it is a forgiving one. The basin is so low that the air at the bottom is noticeably thicker and easier to breathe than elsewhere, as the atmosphere in the world above the rim is now thinning to levels previously only observed above one and a half miles altitude. But as we have seen, the crater is a land of many contrasts, a haven for some, a self-made hell for others. For most, it's somewhere in the middle. Border-dwellers like the unicorn clinging to the steep hills of the valley live on the cusp of the last refuge and the beginning of the end. They watch idly as life around them goes down two paths; some adapt to life in the outside, adjusting slowly to the changes, learning to survive. But many more flee down into the valleys as the landscape beyond them dries up, seeking the comforts they have always known, no way to know that eventually there will be no escape from a world always changing.

The crater might be a sanctuary, but it will not save them forever.