Cuvier’s Isle



Located some sixteen hundred kilometres off the eastern coast of Australia is the isolated archipelago of Cuvier’s Isle, comprised of one large island roughly equal in area to Taiwan surrounded by numerous smaller islets. Highly mountainous, but with a humid tropical climate, the archipelago is a natural labyrinth of forested valleys and canyons shrouded in near-constant sea fog. Believed to have split from the supercontinent of Laurasia some time during the mid-Cretaceous, it, like many far away island systems, boasts exotic native life-forms.



Apart from bats and a few invasive species accidentally brought over by human beings in recent times, its endemic mammals are among the most basal of living species, retaining venomous spurs and laying soft-shelled eggs like monotremes. Birds are extremely diverse, ranging from small flightless jungle rails, fluttering canopy passerines in every shade of the rainbow, to more bizarre forms that seemingly defy classification. Geckos make up most native reptile species, although several species of side-necked turtle and the robust crocodilian-like juro, which may reach over two metres in length, inhabit the islands’ waterways. Insect species are expectedly numerous.



Although common among spoken legends of sailors for centuries, the isle was only formally explored by western voyagers during the early mid-nineteenth century. One of the most unique aspects of its endemic biota were the strange avian-like animals, which shared traits of both bird and mammal. Seen as a missing link between the two groups, they were dubbed ornitherians, at least until near the end of the century when it was realized they were actually living representatives of a group previously known only from fossils, the ancient flying reptiles, or pterosaurs. However, while fossil species may have been flying, all extant species are flightless (although the arboreal mumblers are capable of gliding).



A few species have become extinct in recent times due to human activity, but the islands’ isolation and natural geology have done their best to see off human encroachment. The various small islets and shallow coral reefs around the main island, as well as near-constant tropical sea storms in surrounding waters form a natural ship barrier, while on-foot navigation of the main island’s interior is difficult due to the winding, jagged terrain that makes up most of its geography. Because of this, much of its life has been maintained relatively intact, a time capsule of an age during Earth’s history when reptiles ruled the world, and the planet last saw the vast shadows of flesh-bound wings.



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The parapigs are the isle’s most common tetrapod herbivores, and as their name suggests, vaguely resemble some cross between a parrot and a pig. Broad toothless beaks help them clip low-growing vegetation, although they also feed on fruit, nuts, fungi, roots, and occasionally insects and other small animals. In all five species, colourful crests adorn their beaks, which are larger and more exaggerated in males. All parapigs are polygamous, and males will fight other males viciously for mating rights. They will normally try and settle disputes with displays, but if this is not enough, they will attack one another with sharp spurs on their front legs; wounds from such fights can be severe, but rarely fatal. Females also have these spurs, which are mostly used as last resort defence against predators. The smallest species, the striated parapig (Psittacochoerus minutus) reaches up to seven kilograms, the largest species, the highland parapig (Cacatuasus ingens) reaches up to fifty kilograms.



The eel-lizards (Anguillasaurus sp.) are four species of legless geckos (unrelated to pygopodids) found in the islands’ waterways, reaching from two to five feet in length. Entirely aquatic, they feed on small fish and aquatic invertebrates, which they capture with fast strikes of the head. The entire body is covered in very small, uniform scales, and ends in a broad, flattened tail for swimming. The earhole is covered in a layer of skin to prevent water from getting in. It is extremely cumbersome on land and so usually never leaves the water, giving birth to live young. The otherwise vestigial forelimbs are used during copulation to help the male correctly mount the female.



The geri (Giraffornis magnus) is the largest animal known from the archipelago; a fully-grown adult can reach nearly seven metres in height with its neck fully outstretched and just over six-hundred kilograms in weight, with its mass kept down with its extremely slender frame and an extensive internal air sac system. They are efficient browsers, able to crop the lower boughs from the extensive forests of podocarps, ginkgoes, and yew that carpet much of the interior valleys. Unable to chew, they swallow rocks to help break down plant matter, and focus on soft, newer growth that is easier to digest. This necessitates them travelling far and wide to continuously find new growth; they are solitary but loose associations of animals feeding together are not uncommon. Female geri watch over eggs incubating in mound nests, but once they hatch, the young must survive on their own. Nests may contain over a hundred eggs each, but perhaps only one or two survive twenty-five years to breeding age. These young have a more generalized form and live in creches as juveniles until it gains the lankier build of adults allowing it to browse the taller trees. Like herds of bird-headed antelope, these juvenile groups live in herds and browse on lower trees and shrubs. Opposable fingers with long claws help them pull down higher branches but are also invaluable defensive weapons; one swipe from the nine-inch long claws of a twenty-foot pterosaur is more than capable of killing a man.



The juro (Suchoides ceracorona) is a large semi-aquatic reptile reaching between five and nine feet in length, averaging around seven feet. Although resembling some large lizard or unusual crocodile, the juro is not closely related to any living reptiles. It wouldn’t be until the mid-twentieth century that relatives of the juro were discovered in the fossil record, linking the species to the previously thought extinct taxon Choristodera. Like New Zealand’s tuatara, the juro is a living fossil and the last of a group that thrived during the age of dinosaurs. True crocodilians are absent on Cuvier’s Isle, and so the juro survives holding onto a niche from which choristoderes have not relinquished in hundreds of millions of years of water-dwelling carnivores. Its jaws are powered by enormous muscle bundles at the base of the skull that result in a very strong bite able to kill most prey items instantly. It feeds mostly on smaller aquatic animals such as fish and crustaceans but will still partake in the tried and true riverside ambush on land animals that come down to drink. An adult juro has little to fear but may occasionally be hunted by devilbirds. Unusually, the juro swims mostly by kicking its webbed hindlegs, while using its tail to steer; however, its limb proportions make it hard for the juro to walk on land, and so aside from coming up to bask, rarely leaves the water. This unusual swimming technique and other anatomical features suggest it may have had a burrowing ancestor instead of linearly evolving from an aquatic animal. Unlike crocodilians, juro gives birth to live young, providing no parental care and will eat their young if given the chance.



The devilbird (Phoneornis horribilis) is the undisputed apex predator of Cuvier’s Isle, capable of standing nearly six feet at the shoulder and weighing up to one-hundred and eighty kilograms. Anything that moves or doesn’t move is a potential prey item, up to and including humans. The attributes of an airborne ancestor, an efficient respiratory system, strong but lightweight skeleton, and powerfully muscled forelimbs to push the body forward, but now no longer constrained by the requirements of flight have created a terrestrial predator the likes of which has little equal in any known vertebrates living or extinct in terms of combined speed and power. Its long legs can carry its body forward in huge strides at speeds of over sixty kilometres an hour and it can sustain this speed for some distance, although it very rarely reaches such a speed in the winding terrain, and its ability to swivel and turn quickly is much more valued. Its huge jaws can crush even the shells of turtles that it sometimes feeds on, but for larger prey seeks to first restrain them with its clawed arms. Lifetime monogamous, although they may forage alone just as often as together, they only breed once every two or three years and have only one or two large eggs per clutch. A low natural population density and incredibly slow maturation (male devilbirds take eleven years to reach breeding age, females, thirteen years) and reproductive rate make them vulnerable to environmental change caused by human activity; however, this slow maturation rate is part of their success, as juveniles are able to occupy mid-predator niches and avoid competing with adult devilbirds.



The stingrats are the name used for the non-chiropteran mammals native to Cuvier’s Isle, which refers to the venomous spurs all of them possess. Their venom is extremely potent and used to defend against the various predators that hunt them. Thirteen species are known, ranging in size from the five-kilogram fireback stingrat (Spinorattoides gigas) to the twelve-gram puffmouse (Byssomus letalis). By general rule, the smaller the stingrat, the more venomous it is, and true to this guideline, the puffmouse contains enough venom to kill a devilbird (a single sting, while excruciatingly painful, usually isn’t fatal to a healthy adult human). As most of the stingrats’ predators hunt during the day, they are mostly nocturnal, although the fireback is an exception, due to an extensive covering of toxic spines (the quills themselves are made toxic by manual application of a special compound over them produced by a gland under the arms) it has little to fear from most predators; its name comes from the intense burning caused by these spines. Some bird species collect shed spines of the fireback to use in their nests as protection. Most have a generalist diet of seeds, fruit, insects, and such, although most species have some preferences; the long-snouted stingrat (Megalorhinus steineri) for instance, feeds mostly on insects and soft-bodied invertebrates, with large claws for digging them out, a sensitive nose to sniff them out and a long sticky tongue to lick them up (which is also sometimes used to lap up nectar). Several stingrat species are threatened by the accidental introduction of invasive rodent species, however, these are considerably more easy prey for the numerous predators of the isle than stingrats so their presence is not as damaging as in many other locations.



The wagler (Archaeogavia aquaticus) is a semi-aquatic species of pterosaur about the size of a large duck, and the one that helped to link the “ornitherians” to the ancient fossils of flying reptiles. The wagler retains the original wings of its ancestors, but these have been modified like the flippers of penguins for underwater locomotion. It moves in water with efficient flapping, steering with its lobed feet. A long beak tipped with hooked teeth snag slippery aquatic prey, which are swallowed whole. It moves on land with great difficulty, sliding on its stomach and kicking itself along with its back legs. The wagler avoids competing with piscivorous birds by niche partitioning, and hunting at night (which also helps it avoid predators), sleeping during the day in burrows. It is therefore rarely sighted, but actually rather common along the larger rivers and ponds of the isle, sometimes forming colonies of several dozen stretching for tens of metres.



The rambeast (Rhinopelta brutotherium) is a large herbivore closely related to the smaller parapigs, reaching seven feet in length and nearly three-hundred kilograms in weight. The antithesis to the geri, the rambeast is a squat, heavily-built low browser and grazer, feeding mainly on the ferns, fungi, and shrubs (usually avoiding grasses) that grow under the trees. To reach its favoured food, it will bulldoze smaller trees and unsuitable flora, inadvertently creating trails through the jungle used by many other animals. In the time of dinosaurs, many pterosaurs had elaborate crests, but these were limited to lightweight structures because they still needed to be airborne. With this limitation removed, the large growth on the beak of the rambeast can be solid and heavy; a multipurpose tool, it is used to help uproot plants, in fights with other rambeasts, visual display, and defence against devilbirds. The rambeast has a reputation as an aggressive and short-tempered animal, often attacking with little or no provocation; they may sometimes feed on parts of animals they have killed, but it’s not believed that they actively hunt prey and more happens to be incidental scavenging of animals that happened to have been killed… by themselves. The neck is very short and muscular to hold up this horn (but contains the same number of vertebrae as the geri). Inhabiting the lowland forests and wetlands, it forages solitarily or in pairs, sometimes aggregations of up to a dozen may form temporarily. Its thick beak is useful for cracking open hard nuts and cones that always litter the forest floor but is also perfectly capable of snapping the limbs of attacking devilbirds… or humans.



The mumblers are three species of tree-dwelling pterosaurs which have fleshy membranes connecting their fingers like bats. These are not the original wing membranes of their distant pterosaur ancestors and mumblers evolved from a wingless animal, similar to how whale flippers did not directly descend from fish fins. However, they are only capable of gliding using them, as they don’t provide sufficient lift for powered flight. Living almost entirely in the canopy, they can travel great distances quickly by gliding between the branches, and clamber with long hooked claws, although they are unable to branchiate. However, far from being cumbersome on the ground, they are able to fold up their membrane to move about without it obstructing movement. They move about in groups, which vary from the monogamous pairs of the red mumbler (Sermornis rufopterus), to the clans of the yowler (Plenodactylus vespertilioides), which may number over three dozen. They prefer to feed during the twilight hours to avoid their chief predators, large birds of prey, like the endemic siren eagle (Mooreaetus cuverii), which preys heavily on them. They are named for their vocalizations, which consists mainly of soft chirps and warbles; in the case of the yowler, also have loud screeching used to communicate over long distances, which sounds uncannily like human screaming. The sun above Cuvier’s Isle rises and sets to the echoing cries of yowlers in the canopy below. All species feed mostly on fruit, soft plant matter, and insects.



The heronlord (Gracilitherium prodigialis) is a particularly bizarre animal, standing almost seven feet tall, but weighing only fifty kilograms, the wading pterosaur is extremely slender, with very long legs, a needle-like beak, and thin neck. Almost unbelievable to think that it is one of the closest living relatives of the devilbird. It specializes in feeding on small bottom-dwelling and burrowing animals such as annelids, freshwater shrimp, large snails, small fish, and insects. The long teeth that line the tip of its beak are useful for snagging wriggling prey or removing a snail from its shell. They can sometimes be seen combing the rare beaches that Cuvier’s Isle has during low tide for exposed animals in tidepools or in the sand. Its beak is not adapted to tackle larger prey, but it has been known to hunt bird chicks and stingrats rarely. Although very ungainly in appearance, they are surprisingly fleetfooted when prompted and also capable of swimming to escape danger. Because the prey it feeds on is rather selective, it is territorial and abhors the presence of other heronlords outside of brief mating, although they may temporarily tolerate one another when foraging on the coast. Young heronlords are less gangly than adults, but otherwise similar, living in tree cover and tall reeds for the first few years of their life. They will often dive into the water when startled, a behaviour which becomes much less common in adults.



More than a hundred species of bird are native to the isle and dozens more present as vagrants and coastal nesters. Over millions of years numerous birds have flown over from surrounding landmasses; perhaps once long ago, pterosaurs flew over Cuvier’s Isle, but today birds are the uncontested rulers of the archipelago’s skies. With a wingspan of up to six feet, the siren eagle is the largest avian predator, capable of hunting the smaller parapig and larger bird species. The eagle often forages along the coast, preying upon the abundant seabirds that are omnipresent in the waters around the archipelago and scavenging anything that washes up from the sea.



The unusual piper finch (Allocinclus serocrus) is a species of derived passerine, first mistaken as a species of wader. It feeds on small insects and invertebrates near bodies of water and will sometimes wade into the shallows with its long legs. The sorbet mero (Todoides arcopenna) is one of several species of colourful insect-eating birds related to bee-eaters known as mero native to the islands and resembling the more distantly related todies and motmots of the New World; they often perch upon larger pterosaurs, hunting the insects that follow them, and in turn offering sentry watch against the devilbird.



The ginkgo parrot (Olidopsittacus ginkgophilus) is an endemic species of psittrichasiid which feeds heavily on ginkgo fruit; the trees are widespread on the islands because a large portion of its endemic pterosaurs and several species of stingrats consume its leaves and ‘fruits’ (even carnivores such as the devilbird), but the parrot is the only known bird in the world to specialize on it. Likely as a result, the bird is reported to smell rancid and as a defence is known to spray its fetid feces at its enemies. Also, perhaps related is its taste for ginkgo fruit is its taste for animal flesh, and the parrot is a common sight on carcasses, sometimes attempting to mob larger birds of prey from their kills or harassing injured and weak animals in flocks. The largest endemic avian, at up to fifteen kilograms, is the royal rail (Rallorex viridis), which was originally thought to be a giant rail, but later turned out to be a far more primitive bird. It nests in mounds similar to megapodes and retains spurs on its short wings for fighting. It feeds on seeds, grass, and insects in large flocks on the highland savannah, able to crane their necks high to watch out for predators and having long legs to quickly run for cover at the sign of a threat. Having few defences besides running, they are very good at running, capable of keeping pace with devilbirds long enough to disperse into denser brush most of the time. Despite not being a real rail, it often forages in association with flocks of rails, which rely on them to watch for predators.



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Basically a dinosaur island but instead of (non-avian) dinosaurs, there are flightless pterosaurs.