Orthrocaris

Ryl Madol is not just a nightmare for its brave explorers but also for the average taxonomists, whether they study the animals live on the island or preserved in formaldehyde from the safety of their comfy university offices. Evolution has taken its very own unique path here, often with entire groups which are elsewhere only known from fossils. The end result are thus forms and combinations which defy all of our anatomical borders.

One of the most enigmatic of these is little Orthrocaris antebabylonensis, or Insanity Fish, curiously often found swimming within the pools and swamps which form at the center of the ancient, ruined plazas and their flooded sewers. There can be no other way than to simply describe it as a chimaera. At the front, a soft, bivalved, gill-bearing carapace, very much like in a phyllocarid crustacean, gives rise to two segmented arms and a head with two compound-eyes. So far, so arthropod. But then the mouth is ringed by four or more unsegmented little tentacles, very much like in a cephalopod. The hidden mouth itself is a single claw-shaped mandible similar to that of a velvet worm. Behind the carapace then emerges an elongated, eel-like body, with a dorsal and ventral fin running down its length. Though this body is soft, on the inside it contains a stabilizing organ which unmistakably resembles the chorda dorsalis of our own phylum. What can be said of such a creature which wildly mixes traits or arthropods, cephalopods and chordates? It is the invertebrate(?) equivalent of a platypus.

That nobody has been quite able to shoehorn this little monster into any taxonomical drawer is not surprising. Some claim the arthropodal characteristics outweigh the others, arguing that this may be some archaic member of that phylum that simply evolved the other traits through convergent evolution. Others argue that a chorda dorsalis classifies Orthrocaris automatically within the Chordata. The truth may literally lie somewhere in-between. Some have noted a resemblance to the Cambrian organism Nectocaris, which used to be similarly reconstructed as a chordate with the head of a bug. However, these reconstructions have long been deemed erroneous, as better-preserved fossils of the organism instead suggest that Nectocaris looked more like a flattened, two-tentacled squid. The resemblance to old reconstructions may thus only be a coincidence. Others have suggested a possible affinity of Orthrocaris to the Vetulicolia, who did greatly resemble an odd mix of arthropod and chordate. The cladistic placement of Vetulicolia is itself highly debated and no known vetulicolian fossil is known to have possessed limbs or tendrils as Orthrocaris has, so this affinity also remains entirely speculative. Said limbs most resemble the scourges of Cambrian legless arthropods like Leanchoilia. If recent genomic studies turn out to be true and Deuterostomia is indeed not a true group, then Orthrocaris may be the descendant of some unknown basal group of the alternative chordate-protostome clade Centroneuralia. In other words, it could, in a sense, literally be the ancestor of all groups discussed. Perhaps it could even be the result of some hybridisation accident, back in some dark Cambrian days when the genomes of all the phyla were still similar enough for such taxonomic bastards to come into existence.

Regardless of its classification, contact with Orthrocaris should be avoided at all costs unless one is properly protected. Although the organism is only as large as an index finger, the bite of some individuals is lethal. Not because it is venomous. For some unknown reason, the saliva of the organism carries a prion inside it. Prions are misfolded proteins, which can cause other proteins to misfold in the same way, allowing them to pathogenically reproduce almost like viruses. There is no known treatment method for prion diseases, so 100% of all infected end up either dead or severely disabled for life.

Like mad-cow-disease, the Orthrocaris-prion is neurodegenerative, meaning it attacks the human brain. It can lead to insanity, followed eventually by brain-death. Some infected have been reported to have escaped their containment and in a mad rave wandered out into the island, only to return days later, with almost no scratch on their body. The animals on the island (who seem to be immune to the prion) show no interest in attacking infected humans. Most shockingly, those patients who escaped without a protective mask on suffered no ill effects from the island’s toxic spores. It seems almost like a sadistic twist that only this disease grants humans the ability to survive on Ryl Madol, but at the price of a short life of insanity. The Headtakers, never too fond of outsiders, have by now discovered the disease’s cause and effect and weaponized it. Using the snake-like glottis in their lower jaw, Headtakers are capable of using blowpipes. When they are feeling especially sadistic, they will carry a leathern waterbag full with little, living Orthrocaris with them, remove the “fish’s” tiny arms and shoot them through the pipes at the necks of unsuspecting humans.

The most bizarre aspect of the prion is just how it cripples the brain. In most cases it mainly affects the areas responsible for language processing, making the infected eventually incapable of talking in coherent words or sentences. Instead, they all start spouting completely unintelligible gibberish. However, all those infected speak the same gibberish and seem to be able to understand each other to some degree, while suddenly incapable of understanding their healthy colleagues. In the early stages of the disease, before they lose the capability of speech completely, they can be heard in their quarantine cells seemingly conversing with each other in undecipherable but still distinctive words and phrases like “Oadriax!”, “Dilzmo!”, “Cordziz”, “Agtoltorn parach asimp!”, “Pappe hasatan, pappe hasatan aleppe” and “Rahel mai ameche zabi almi”. I imagine this must surely be of interest for neurolinguists, but they have not returned my calls.

Castorosaurus

Ryl Madol is able to support a large amount of amphibious and aquatic life thanks to its many pools, ponds and streams which pay tribute to large lakes and rivers. For many of the tetrapods and arthropods, these are vital for their reproduction, as their eggs and larvae lack shells and need to be laid in water. However, many of these breeding pools are not necessarily provided by the island topography. They are made by the wildlife itself, though, ironically, not by amphibians.

Encountered in almost every waterway are waterlogged wooden structures, which early explorers at first mistook as as bridges or fish-traps created by the island’s intelligent natives. But no. These are dams built by an aquatic reptile called Castorosaurus, whose name literally translated to “beaver-lizard”. Castorosaurs are derived members of the Captorhinidae, a group of Palaeozoic reptiles that, on account of missing postorbital windows, were traditionally grouped with the “Anapsida” alongside the turtles, though recent work has recovered them as being eureptiles close to the Diapsida. Even more recent work has declared them stem-amniotes, though this remains controversial.

Just like beavers, castorosaurs are ecosystem-engineers who prolifically build dams along narrow waterways, creating many pools throughout the island in which other organisms can thrive and reproduce. Their dams usually have a hollow chamber that can only be accessed from underwater. Here the castorosaurs lay their eggs and raise their young. The dam structure prevents terrestrial or aerial predators from easily gaining access to the nest, though the parents still tend to be on the look-out for any of the creeping amphibians that may dive and slither below.

Unlike the terrestrial captorhinids of the Palaeozoic, castorosaurs feature many aquatic adaptations such as webbed feet and a dorso-ventrally flattened tail like a platypus. This tail-shape is of course quite curious, as reptiles usually swim through sideways undulation and so one would expect a laterally flattened tail, but the tail seems to be mainly used as a sort of hammer in dam-building. What castorosaurs have retained from their ancestors are the long, kinked snouts with specialised teeth at the front. Said teeth have become quite large and spiky. Many people easily make the mistake of assuming that castorosaurs used their large front-teeth just like beavers to gnaw at wood, but that is in fact incorrect. They are entirely unsuited for such a task and are instead used to capture fish.

If they cannot gnaw at trees and branches, where do castorosaurs get the wood for their dams then? The answer is that they simply pick it up from the forest or lake floor and so do not need to saw up fresh wood. But why it is that simple for them is actually interesting. Vast areas of Ryl Madol are covered in thick carpets of wood-litter that degrade into smaller pieces over time as animals trample over them, but never truly rot and decay. Some pools and moors have as a consequence devolved into large, malignant peat bogs in which unwary animals may stumble and get trapped. It is highly unusual and not something seen in any other forests in the world. Only recently has the reason behind this been revealed by botanists and microbiologists: Ryl Madol entirely lacks any organisms, be they bacteria or fungi, that can digest lignin, the main polymer that makes up wood. This used to be true for all of Earth in the Carboniferous period, from which huge coal deposits still survive. While it explains the primordial nature of Ryl Madol’s forests, it just opens up many more questions. Why has lignin-digestion never evolved or arrived on Ryl Madol? Or did it exist here once but the respective microorganisms have since somehow gone extinct? The lack of notable coal deposits in the island’s geological formations may be evidence of the latter, pointing towards this being a fairly recent development. It seems almost like time on the island is moving backwards.

The Natives

Intelligent life has evolved on Ryl Madol and it is not pleasant. Since some of the very first voyages of discovery, a species of reptile-like creatures has been encountered on occasion, but it is just as hostile as the rest of the island. These creatures, Uromanus yigi, have never shown interest in making friendly contact with humans and instead try to kill most of them on sight. No definitive settlement of theirs has ever been identified. In their attacks on unsuspecting stalkers they often seem to crawl out from the jungle’s thicket or the dark crevasses of the ancient ruins. Based on some accounts, it seems possible that they house deep beneath the earth in the many tunnels, caves and catacombs that wind their way through the island’s underground.

A Headtaker, donning the skull of an unidentified synapsid and surrounded by its latest trophies.

The common names that have been given to them are “Headtakers” or “Decapitators” because they seem very fond of beheading other man and beast alike and using their heads as decoration. Almost always they are seen wearing skulls as helmets or other ornaments.

Biology and Origins

As studying them in life has proven extremely difficult, most of what we know about the Headtakers’ biology has come from dead specimens. The most striking feature of the Headtakers is that they completely lack any hindlimbs. Unlike whales or snakes they do not even have vestigial bones attesting to their former existence. Instead of legs, they use their long arms to walk. These end in raptorial “feet” with four clawed digits, in addition to which they also have a large sickle claw not unlike a dromaeosaur. By themselves the “feet” are quite dextrous and can be used to hold and manipulate objects, but for finer and more practical tasks the Headtakers instead use their long chameleon-tail, almost like a tentacle.

Their heads are quite large, holding a roughly human-sized brain. Their jaws are edentulous, having only a sharp-edged beak. The tongue is mobile and the larynx inside the throat complex, probably allowing the Headtakers some degree of verbal communication. On top of the snout were found receptor-pits for infrared-vision, similar to some snakes.

What exactly the Headtakers evolved from has been a surprisingly difficult question. At first glance, their scaly skin makes some type of reptile the most obvious. As the back of their anapsid skull lacks any fenestrae, an affinity with the Parareptilia has been suggested in the past, putting the headtakers close to bolosaurs, pareiasaurs and perhaps even turtles. However, the body of at least one pregnant female has been dissected, which revealed unlaid eggs inside the abdomen. The eggs were soft and gelatinous, like a frog’s spawn. This suggests that the headtakers actually reproduce like amphibians, perhaps rearing their tadpoles in unseen underground spawning pools. If true, this means their origin must lie outside Amniota, most likely inside the Reptiliomorpha like so many other of the “reptilian” creatures on Ryl Madol. A few of the more serpentine “microsaurs”, a polyphyletic group made up of lepospondyls and other stem-amniotes, have been suggested as possible ancestors.

The only genetic study done so far has not recovered any satisfying results that favour either the true reptile or basal reptiliomorph origin. A minor caveat the authors added to their paper is that if some additional traits are taken into account, the genome of Uromanus may actually suggest an origin outside the Tetrapoda, them having instead independently evolved out of a sarcopterygian more closely related to the Dipnoi (lungfish). These results have been heavily criticized due to the methodology that was used. The issue may never be resolved until their tadpoles are found and studied.

Material Culture

Headtakers are capable tool users, using flint and even obsidian to craft tools and dangerous weapons. From afar they have been observed fishing using harpoons. Pitfall traps have also been encountered on occasion, leading to many stalkers’ deaths. If these traps exist to hunt animals or to specifically kill humans is not known. Bows or slings are unknown, the main throwing weapons are long obsidian-tipped spears and javelins, which they can throw with enough force to pin an unsuspecting adventurer to a tree.

Fire and how to make it is known to them. Many lost explorers have wandered towards smoke columns emanating from the forests and hills, thinking they found a human encampment, only to find an empty hearth over which one of their headless crewmembers has been roasted.

They wear no clothing, perhaps having no need for it with their scaly hides in this warm climate. But they do wear ornaments, most prominently bones and skulls of other animals. Across the island can be found stakes and even totem poles adorned with cut-off heads, including those of humans.

Perhaps due to the proclivity of collecting and presenting trophies, the Headtakers seem to have a form of hunting culture, perhaps hunting as a form of ritual or perhaps even leisure. As a consequence they seem to have at least some form of code. During ambushes of stalkers or research-camps, people that are encountered without weapons or otherwise vulnerable are usually left unharmed, while the skulls of those that defend themselves are gleefully collected. This may be a form of mercy… or perhaps unarmed humans simply make for boring prey. 

Apart from this, virtually nothing else is known about the culture of these beings, except for one disturbing account, which is soon detailed. As already discussed, it remains unclear in what way they may be related to the vanished culture from which the island’s ruins originate, though they certainly know their layout well and may even use them as dwellings.

The Sacrifice

In February 1928, a single man holding onto a piece of wood was fished out of the waters off Sumatra, barely alive. His name was Eliah Hansen. His account is the only one we have of what may be going on deep below Ryl Madol. He was a Danish sailor aboard the Dutch fishing vessel Sara, which that month crashed into a Rylian reef during a storm at night. With the lifeboats, all the sailors were able to evacuate onto the island, but there they were almost immediately ambushed by the Headtakers.

Surprisingly, the Headtakers did not kill them immediately, but instead captured them and tied their limbs together with ropes. The sailors were then each carried off deep into the jungle, until reaching the foot of a black step-pyramid. Through a gate, they were carried deeper into the labyrinthine catacombs until reaching what must have been some kind of underground settlement.

Hansen’s account of what happened in there is horrific. Several of his crewmembers were beheaded immediately with a toothblade-axe on a rock altar that had been stained red with the blood of previous victims. He observed juvenile Headtakers playing with the heads, while the adults ripped out their teeth, perhaps to use as jewelry. A few other crewmembers were flayed alive after being tied up to poles. When they screamed too much from the torture, their skulls were simply bashed in with clubs, the Headtakers seeming merely annoyed by the noise.  

The rest of the crew, including Hansen, were carried deeper into the chambers, until reaching the ledge of a vast grotto, its bottom filled by a deep, dark lake. There they were put into a cage made of large rib bones. A dark ritual commenced. Fires were lit and large, hollowed-out tree-trunks were erected, against which the headtakers banged their clubs, producing a rhythmic drum tune. This primitive music was accompanied by rattle instruments. In snake-like voices, the Headtakers began to sing in a language unknown to man, which endlessly echoed through the cave. One of the sailors was then seized and dragged out of the cage, to then be strapped onto a wooden mechanism. This crane lowered the poor sailor over the lake and as the drumming of the logs grew louder, the serpentmen began to repeatedly chant what appeared to be a name: “Yig! Yig! Yig! Yig!”

What happened then, Hansen was very apprehensive to tell. He himself instinctually averted his eyes, but the other sailors saw it and subsequently lost their sanity. Some indescribable horror, which he thinks was the “god” of the Decapitators, must have emerged out of the lake. When the chanting and the drumming was over, the sailor on the crane was gone. This continued for the following days, until only Hansen and another crewmember were left.

When it was their turn, Hansen managed to break off one of the bones of the cage and the two secretly sneaked out while most of the Headtakers were asleep. Unfortunately, they accidentally alerted some guards, leading to the impalement of the remaining crewmember. Only Hansen himself managed to escape the labyrinth and ran towards the coast. Only finding a log of wood for himself, he swum out to sea, thinking that drowning was better than dying at the hands of these creatures. That he was later found by another fishing vessel was rather miraculous, as is the fact that he seemed to have had some natural resistance to the toxic effects of the Rylian spores.

Later that same year, Hansen was found dead in an inn in Antwerpen. With him went any further chance of getting to know more about the Headtakers’ underground rituals. The cause of death was an obsidian dagger impaled through his heart. The murderer remains unknown.