The Meridian Islands

265 Million Years PE

The Meridian Islands were a volcanic chain of three islands along the equator, one quite large and two smaller ones adjacent, that began to form from a late burst of volcanism in the middle of the ocean some 35 million years ago during the late Pangeacene. These Islands were already well-formed at the start of the Ultimocene, after which time the hot spot that formed them cooled and closed and the islands began to shrink from erosion. Lowering sea levels during the middle Ultimocene, however, have greatly increased their size once more as formerly submerged coastal shelves are now left high and dry. This has also had the effect of bridging these three formerly separated land masses together as one, allowing endemic species which had evolved for up to thirty million years in isolation from one another to mingle.

The islands today are one of the most mild environments left upon Serina even as it plunges into a harsh ice age, owing to its equatorial location. Though tundra covers its north, the south and western portions of the island support healthy forest with cool but stable temperatures. Even so the island's stability is only relative; like everywhere else upon the world, ongoing climate change has still had a devastating effect on these islands' biodiversity. The current assemblage of plant and animal life is an eclectic mix of old, adaptable lineages which have adapted to the many changes, and newcomers from other places which have only just arrived. Particularly worth mentioning is the unique case of these islands being populated with several lineages of unique land animals that evolved from almost fully aquatic marine animals, in addition to flyers. The resulting disparity of life leaves the Meridians in the mid Ultimocene a fascinating place, full of highly distinctive creatures caught up in rapid change and doing their very best to keep up.

The Southern Forests

The forests of the Meridians are temperate, but except in a narrow band toward the north of the islands they are not deciduous, even though many are comprised of broad-leaved sunflower trees. This is because the climate is not seasonal at these latitudes near the equator; day length changes but the sun is always high in the sky and its angle is unwavering. So while the north of the island where tundra occurs experiences shorter day length and cold winter temperatures, the southern forests stay almost exactly the same no matter the month. But global temperatures are now cooling, and so while these regions lack a harsh winter, they get no warm summer either. All such forests along Serina's equator in this period are thus constantly cool, averaging fifty five to sixty five degrees Fahrenheit (13 - 18C) the year round with minimum temperatures still above freezing and high temperatures never surpassing seventy five degrees (23 C). Plants can thus still grow throughout the year here, albeit less quickly than they could in a warmer environment. Flora of these southern forests are descended from both tropical evergreen trees which have adapted to endure a cooler climate and from deciduous species from the north that moved south in response to climate change, adapting to no longer require their winter dormancy.

The forests in the southern coastal region of the Meridians may theoretically get a lot of sun from their equatorial position, but more often than not the days are dreary. It rains roughly half the days of the year here, with no seasonal highs or lows, and windy ocean storms that make land fall are relatively common, which often bring in lost migrating birds to the islands' shores. The climate of the south of the islands is a cool, damp one where the sky is rarely clear; when it is not raining, the sky is still often overcast with white clouds that hide the blue skies except in brief and passing instances. But this moisture makes these islands, like the similar forests on the southern coast of Serinarcta, very rich in plant life; epiphytic plants grow in great diversity upon the branches and bark of the larger trees, while the ground is plush with thick growths of moss and other plants that thrive in wet and shady conditions. A great diversity of fungus is apparent, the wet conditions allowing them great ease of reproduction and so a huge variety of mushrooms are easily found here, some of which are important food sources to animals while others are highly poisonous. The islands' undergrowth teems with arthropods distinct from mainland forms, particularly terrestrial crustaceans which evolved here to fulfill many of the niches filled elsewhere by insects, many of which struggled to reach this landmass due to its extreme isolation before receding sea levels brought it closer to the mainland. Many of these crabs are entirely arboreal and independent of the ocean; some among these were able to grow quite massive, among the largest land arthropods ever to evolve by leg-span, while others have evolved exquisite camouflage to avoid their enemies - or stalk their prey. Ants were historically absent on the islands and crickets too arrived only recently; filling similar roles in the ecosystem to such insects are diverse isopod species evolved from aquatic groups which scuttle along the wet mossy ground like cockroaches, scavenging any edible detritus. Some of the smallest of these have become specialist parasites of birds, living in their nests and drinking their blood, while others are beneficial and remove shed skin cells and feces and other detritus from the nest.

Most of the land vertebrates native here are birds, because no molodonts, or indeed most tribbetheres, were able to reach these islands until less than two million years ago; the native molodonts now are thus very little changed from their ancestors and little larger than rats. Yet like rats, these recent colonists eagerly fed on birds' eggs - and the birds here were naive to them. Many had lost the ability - or never evolved it at all - to carry their eggs away from danger like on the mainland and so many small bird species went extinct on the Meridians as a result, meaning most modern flying birds to be found here are either recently arrived new colonists or come from the metamorph groups and do not incubate their eggs at all. Not all have stayed small: the pitpocket is a long-legged, one hundred pound descendant of little shore-scavenging sparrowgulls, which lives in groups in the southern forests and feeds primarily on mushrooms. Its ancestor arrived on the islands just ten million years ago, rapidly lost its means of flight, and adapted to run entirely on the ground because food was so readily available that flight was no longer necessary. But the pitpocket evolved from highly intelligent modern birds, and so differed much from other rapidly-evolved flightless birds which have evolved on Serina before such as the Kyran chubbirds or mainland womblers. It grew large but not stupid, because on the ground where it chose to live it still had predators...

Life on the Meridians is far from paradisaical for its flightless birds, as these rich temperate rainforests hide many dangers.

Before even molodonts reached the Meridians there were other animals that would eagerly eat the pitpocket ancestors' eggs: eelsnakes, which rafted here as semi-aquatic species more than twenty five million years ago, and nowadays the even stranger burrowing burdle, which followed a similar but more innovative evolutionary history. This burdle - the only member of its entire clade to become secondarily terrestrial - began to evolve from an entirely aquatic species more than 30 million years ago. Though the largest and most formidable burdles alive today are members of a live-bearing group, egg-laying species have survived in lesser abundance throughout the Pangeacene and Ultimocene. The burrowing burdle evolved from one such species which would come ashore onto the beaches of this island chain when it was new to lay their eggs in very large colonies, and gradually learned to dig up the nests of the other burdles which were there before them for a rich and nutritious meal before going back out to sea. Spending a little more time on the beach every nesting season, this particular species shrunk in size and its flipper-like forearms angled forwards so that its elbows pointed upwards and its wrists angled in, allowing it to stand more upright and to walk rather than drag itself by its flippers, and letting it dig more efficiently too at the expense of its swimming ability. The tip of the flipper keratinized into a spade-like digging tool. It specialized as an egg-eater on the beach, using a wide gape and a ridged beak to crack even quite large eggs, and became a predator of the burdle nesting grounds which supported nests all year round due to the tropical climate.

The burrowing burdle, probably the most aberrant of any of its order, is especially fond of eggs and is well-adapted to break them, but it feeds on any small animals that are slower than itself, as well as certain mushrooms. It lives in burrows on the forest floor, often near freshwater in which it can still dive and flee from enemies, but it no longer lives near the sea. It joins the ranks of a select few other birds able to walk with a quadrupedal gait, made possible by its extremely derived anatomy. The shoulder blades have lowered so that they are not so close to the neck, and the shoulders have rotated around halfway, projecting outwards like a turtles', so that muscles once used to pull during the ancestral canary's flight stroke are now used to push against the ground.

Spending less and less time in the water because of this ready supply of food on land - both burdle eggs and newly-hatched chicks - when the climate began to coo too much for the beaches to incubate their eggs and the last egg-laying burdles besides itself began to go extinct, the now fully terrestrial burrowing burdle moved further inland and broadened its diet. It hunted arthropods and molluscs and the eggs and chicks of ground birds and now shelters from the coldest days underground. To incubate its own eggs, it has developed similar metabolic specializations to the larger aquatic burdles that pushes it toward an endothermic metabolism. Through a specialized shivering reflex, it can raise its body temperature up to ten degrees above ambient air temperatures, letting it keep its eggs warm enough to develop and hatch. Unlike most true endotherms however, it does not maintain a constant temperature and primarily does so only when brooding eggs; at other times it is much more more energetically efficient to live live at a somewhat slower pace at ambient temperatures, which allows it to require much less food. It basks in the sun, when it appears at least, like a reptile for solar warmth and is very dark in color, nearly black, to maximize its absorption.

To avoid the burrowing burdle today, the pitpocket no longer makes any sort of nest to have raided. It has taken the egg-carrying instincts of its forebears to their logical extreme and now the female holds her large eggs, always laid in pairs, with her at all times during its incubation. Her wings are entirely useless to fly at her great size, yet remain large and very strong for a very different role. A fold of bare skin on the inside of either elbow has evolved which forms a sort of pouch in which the eggs is transferred immediately after laying and there kept until hatching. When the wing is held against her feathered chest, this pouch is insulated and quickly reaches her body temperature, keeping the developing embryo warm and safe from any and all enemies. Because her wings are otherwise of no use this does not seem to inconvenience the female pitpocket whatsoever as she forages for food using her beak and feet alone as most birds do; tendons in her wings even lock them into this position by default so that she does not drop her eggs in her sleep.

The pitpocket is not especially huge among Serinan birds extant or extinct, but it is among the largest sparrowgulls, which rarely produce such flightless forms. Females incubate their eggs in pouches on the inside of their elbows: the eggs are illustrated in an exposed position for clarity, but in life the wing would most often be held folded up, and the eggs hidden.

The male pitpocket is similarly colored to the female, but has more contrasting black and white barring on the chest and a red, rather than salmon colored, neck. Though entirely terrestrial, the pitpocket still exhibits the tube-like nostril structure its ancestors evolved to excrete salt from the seawater they drank. The salt gland is now vestigial, but the structure - otherwise benign - has persisted, albeit now much smaller than in the ancestral sea bird.

When the semi-altricial chicks hatch (which she must feed and attend to just as her ancestors fed their young in nests) she carries them too until they are fully strong enough to run alongside her, and even after they can they will continue to be picked up and carried to rest for several months, well after they no longer fit into the mother's wing pouch and she must instead hold them in a tight bear hug. The male, for his part, takes no role in parenting. His job however is no less important; he defends the females - in harems which he maintains through contests of strength with other males - from predators. And on the Meridian islands in the mid Ultimocene, there is one sort of predator which is particularly threatening: the terracudas, or flightless predator tribbats.

Tribbats are the only tribbetheres with powered flight, and so unlike all their relatives they made the ocean crossing to the Meridians relatively easily and fairly early in the islands' history. Dividopterans, and more specifically close ancestors of the aeracuda - were blown here twenty million years ago. They found a world with no predators larger than themselves where fat, flightless birds proliferated by the millions. They spent more time galloping on the ground to chase them down and did not need to fly, so there was no selective pressure to stay able to do so. Over millions of years their wing digits shortened and their skin membranes diminished; a unique, endemic group became entirely flightless within ten million years, though the process was more gradual than in flightless birds; it occurred more through gradual genetic drift than rapid loss, because they walked on their wings anyway and so could not simply lose them entirely in a few quick mutations; they only gradually shortened their fingers and patagia. Not all of the grounded tribbats stayed predatory; one group, all of which are still rather small, eat mostly fruits and seeds and have evolved lavish sexual displays using their wings for show. But the tribbats that the pitpocket fears are very different. The terracudas are active predators; built like the aeracuda with vicious extensible jaws, but no longer constrained in size by the need to stay airborn, these large carnivores are very formidable threats to the island's flightless birds.

The shadowstalker is the largest tribbat, able to stare a grown man down eye to eye and weighing as much as 230 lbs. It is a solitary, nocturnal predator of animals up to half its own weight, which it hunts primarily by sight but also by an acute sense of smell, though it primarily feeds on animals much smaller which it catches in the undergrowth and eats whole. Completely flightless, it has lost all of its wing digits and has only the smallest vestiges of its skin membranes so that it can gallop after its prey without getting caught up in vegetation. The adult is well-adapted to walk on all threes, but the young still cling to their mother for their first several months of life, using grasping wing claws that gradually become stronger and less hooked with age to allow for a life of terrestrial walking.

There are two extant species, but were once as many as six that co-existed on different islands in the chain; the two survivors also evolved separately over more than eight million years and have only again met recently as sea levels opened land bridges between their native lands. Time has shaped each differently from their ancestors, but the family resemblance is still acute. The shadowstalker is tall and sinister, up to six feet high at the head, and stalks alone in the forest by night, taking its prey by surprise in elongated jaws lined with sharp, hooked teeth that grab tight and never let go. The diurnal slasheratu meanwhile is much smaller, twenty five inches or so at the shoulder, but no less formidable because it hunts in loosely-cooperative mobs, killing its prey with both a proportionally stronger, less extended jaw and long spurs on its wrists that it jams into the neck of its victims. The male pitpocket which leads the group is strong enough to fend off the shadowstalker alone if it is not taken by surprise, but the slasheratu hunts in numbers and can overwhelm even such a formidable target. To survive this threat, the entire group must stay on alert and close together; the predator will only attack one that has become isolated, as even a group is no match for a whole herd. Both predators live in a chaotic balance with both their prey and one another, and are highly hostile towards each other. Each is able to kill their estranged relative during conflicts depending on circumstance, so they avoid one another if possible. This may be why the slasheratu is now diurnal even though it shares many of the shadowstalker's nocturnal adaptations, such as keen eyesight that sacrifices low-light acuity for very poor color vision.

Gregarious by necessity but still highly aggressive, the small, fast slasheratu is a fierce predator but is frequently disfigured through scraps with its own kind over food. These smaller terracudas do not particularly like one another and their cooperative hunting is selfishly motivated, with the most dominant individuals eating kills first and fighting fiercely if contested by subordinates. Slasheratus are almost always scarred, often with ears missing, and occasionally kill one another in such skirmishes. The thick mane that covers the neck may have evolved to protect from injuries inflicted by others of their species.

Both males and females are aggressive; there is no difference in size or status and either sex can be dominant or subordinate. Despite their aggression hunting in groups increases their success rate and allows them to tackle animals much larger than themselves, so the behavior persists. Prey is killed primarily through shock and blood loss; slasheratu are nimble, able to leap onto and off their prey faster than it can react; they "hug" their victims, jabbing their large thumb spikes into the body and bursting arteries, sometimes breaking the spinal cord. The jaws are strong, wide, and adapted to tear flesh at the extent of their extensibility. They are attracted to the scent of blood and will attempt to steal carrion from other carnivores through their large numbers.

The terracudas are perhaps the most unique carnivores on this strange island chain, but they are not the only threats the pitpocket and other flightless sparrowgulls face... and neither species is the biggest carnivore to be found here. In this land of rain and moisture... even taking a drink can sometimes be a fatal mistake. A gigantic species of primitive eelsnake known as the platyconda has called the islands home for almost fifteen million years. Resembling a huge eel, this semi-aquatic swordtail descendant has changed very little over hundreds of millions of years in every way but scale; it is the largest eelsnake ever to live, so the point it is slightly gigantothermic. Thirty feet long, and up to one thousand pounds, they stay a few degrees above ambient temperatures even in the cold swamps and ponds of the south of the island simply because they are so large that their day to day metabolic processes raise their body temperature. Able to breathe both air and water, they have joined a few types of fish stuck between two worlds; they need to stay damp to survive, yet require periodic breaths into a labrynth organ that long ago was part of the stomach, or they will drown. The platyconda is so large as an adult that moving over land as smaller eelsnakes readily do is difficult and so it is highly aquatic, but this does not mean it eats only fish. Though it does hunt aquatic animals, a predator so large requires big meals, and the platyconda favors prey from the land. It lies just beneath the surface with only its elevated eyes exposed, sometimes for days at a time, until an animal comes close to the water for a drink. When the moment is right the playconda launches its flexible neck up out of the water, grabs the victim in its five hundred long, curved fangs, and secures a firm hold upon it it like a snake with muscular coils of its own body until it drowns. It then consumes its prey not whole, but by rolling and ripping chunks of flesh from the carcass. Long lived, slow growing, and with a slow metabolism, just a few pitpocket birds per year can keep it healthy and well-fed. Well-adapted to a limited island environment they have lived upon for a very long time, the platyconda gives birth infrequently and to small broods of just three to six small young, not all of which will grow up, lest they overwhelm their delicate island ecosystems. The young move easily over land and so disperse far from their mothers almost immediately, as she will not tolerate these competitors in her territory for long.

The gigantic platyconda is the Meridian Islands' largest carnivore, though it is not technically terrestrial as it spends its entire adult life in water. Young feed on fish, insects and small tribbets; the adults prefer land animals and can subdue the largest herbivores on the islands. Fortunately for their populations, it exists only at low density; very few reach adulthood as a result of predation from other predators and even their own parents. Juveniles move easily over land on wet nights, migrating to new water bodies often and taking advantage of temporary ponds, but adults are so heavy that they are tied to the water and so remain in larger lakes and rivers. Though it fills the same niche, the platyconda is not related to the large ambushing eelsnakes that also evolved in the rivers of the continents - the two are convergently evolved. Of the two groups the playconda is more terrestrial, at least in its early years, and much less active.