King Mauk

Most of the northern hemisphere of Mars used to be an ocean. Geological and paleontological evidence agrees on that. But is this sea completely gone or can the northern polar cap the planet be seen as the last shield of a lost waterworld? The more this habitat is studied, the more it reveals that this huge glacial shield indeed still houses great bodies of saltwater beneath it. Though some of these are so salty as to be toxic to most life. A few lakes interconnect with each other and possibly underground chambers, creating enough circulation for more complex ecosystems to exist. Standing atop these, with the creaking ice beneath your feet and peering down into the briny blue, one can almost deceive themselves into thinking they’re standing somewhere in Greenland in the winter. But that illusion is broken as one goes beyond the horizon, being greeted by a dry tundra and beyond that the red wasteland.

One of the few Martian animals here which add a certain marine vibe are the king mauks (Areoalca bonomii). These aliens have become quite popular among Earthmen, as they quite adorably resemble penguins, loons and similar waterbirds. The common name mauk is even a contraction of “mars auk”, referring to the extinct auk birds of our planet’s Arctic. That such an alien could come about through convergent evolution is not quite surprising, considering that Nothornitha already have a general likeness to flightless birds. Unlike a penguin and indeed unlike any other nothornithes, mauks cannot actually stand up on their legs. When they are out of the water, they instead always slide on their bellies, with their legs cumbersomely pushing them forward. It is an aspect that makes them resemble seals more than penguins. In some ways this is also an atavism back to the locomotion found in more archaic periostracans.

Mauks live their entire lives upon the great ice shield, exploiting the subglacial lakes opened by seasonal cracks. Should they ever accidentally slide the glacier fringes down into the tundra, they will become forever lost and easy pickings for predators, as they are too slow and clumsy to survive in any other environment. No, these animals, uniquely among remaining higher life of Mars, feel most at home in the water. Here they can be elegant and swift, gently gliding through the brine with the gently paddling kicks of their flippered toes. Most of their diet consists of soft-bodied prey such as selpies, as well as onychognaths. They have also been recorded diving all the way to the deep bottoms of the lakes and raking the soil for worms and sortaxes. It is a glimpse into a world that may have once been. Ironically though, there is no evidence that the mauks are some ancient relic from the oceanic times of Mars, as there is no known fossil record of such nothornithes. Combined with molecular studies on their relationships with the ptannus of the surrounding tundra, this suggests that mauks are, geologically speaking, relatively recent creatures that evolved in response to the new realities of life on the red planet.

It perhaps goes without saying that mauks, living in perhaps the most extreme environment on Mars, are the most cold-adapted of all periostracans. Their skin is covered with a dense, water-repellent fur, similar to some Arctic seals, while their internal carapace is covered both in- and outside by layers of fat. The carapace itself is uniquely honeycombed by small, air-filled pneumatic chambers, which acts as an extra layer of insulation. Using the bone shell as a form of insulation is indeed unique not just among periostracans but among Antitremata as a whole. During the long winter months, when the ice is too thick to go fishing for food, the small colonies of mauks will collectively dig deep burrows into snowhills and hibernate there, tightly cuddled to each other, not unlike the extinct polar bears of yore. In spring, when the ice begins to thaw and starbursts erupt out of the glacier, they become active again and begin diving down into the subglacial lakes in search of food. Once they have restocked their winter fat, they begin to breed.

Uniquely among nothornithes, mauks give “live birth”, though instead of true viviparity they do so through ovoviviparity. This means that the leathery eggs are not laid but are simply kept inside the body inside a well-circulated ovary until they hatch. This is undoubtedly another adaptation towards the cold, as there would be no way in the white desolation of building a nest and mauks do not have the protective skin-pouches of penguins. Mauk hatchlings are highly precocial and already able to swim and slide. The parents encourage their young to forage for food on their own at a very young age, though are still watchful over them. In the water, young mauks may fall prey to rhosons and chelicerous onychognaths, while on the ice they can become easy pickings for flying predators. As adults, they have nothing to fear but the forces of nature themselves.

Mauks have only small brains and their social behaviour seems somewhat stunted in comparison to their Earth counterparts. Their colonies are small and have no organization. As each parent is able to forage for food by themselves when carrying eggs, they also have no need to build nests or form monogamous breeding pairs, which also removes the need for elaborate displays or pebbling behaviour. Sometimes mauks will fight, quite violently in fact, over access to diving spots. During very harsh winters, cannibalism has been reported.

It is a life out in the desolate, white wastes, though evolution does not particularly care if it is a pleasant one. A dull mind is a blessing in these conditions.

Arctic Sortax

 

Peering beneath the ice caps and glaciers of the north pole of Mars can reveal an assortment of many strange creatures. One of them is the sortax, a flattened, cushiony creature with a strangely bifurcated spine out of which grow a tadpole-like tail and two eyestalks. A common urban legend on Earth regarding this animal is that when an astrobiologist, usually only named “Dr. Morris”, if named at all, first discovered this creature, while livestreaming his expedition as a public NASA broadcast, he shouted “Fuck, another new phylum!”. The resulting PR debacle then led to him being fired in most versions of the story. This is almost assuredly a pop cultural myth that is entirely fabricated. The true discoverer of the sortax was a woman by the name Eryx Burton, and there is no comparable recording in any of NASA’s archives (for how the myth may have formed, see Busch 2338).

More importantly, Burton never made the claim that the sortax belongs to a separate phylum, as examination quickly uncovered its ties in the Martian tree of life. The animal’s endoskeleton is made of apatite and silicon dioxide and the anatomy of the tail is identical to the arms of trichordates such as the hortax. The tri-radial cloaca on top of the body is also another dead ringer. It strongly suggests that the sortax is a trichordate, but has shifted away from the ancestral radial symmetry of its starfish-like ancestors towards a bilateral one. Two arms stiffened and became structural supports for an expanded gut and mantle, their tips becoming mainly sensory organs, while the third became a tail. The three-pronged mouth shifted from the bottom of the body towards the front. This is certainly not as extraordinary as it may seem, as on Earth many radial animal groups also have members with bilateral elements, such as ctenophores with two tentacles, or sand dollars and irregular sea urchins among the echinoderms. Like in the latter example, the anatomy of the sortax and its relatives may have originally arisen as an adaptation towards horizontal digging in marine sediments, where a radial body is less beneficial than an axial, streamlined one.

Though it is primitive in its aquatic habitat, the sortax likely does not represent this ancestral state, as it largely lives on top of the sediment and only digs itself into the sand when danger, such as arctic rhosons, presents itself. When on the search for food, the sortax moves by hovering through slight, carpet-like undulations of its flabby mantle, the tail only being used when quick bursts are required. Its main prey include the various worm-like organisms that inhabit the subglacial silt: circulates, pseudarticulates and mollizoans. These are usually devoured through suction feeding, whereby the prongs of the mouth open fast enough to create a brief vacuum. Swallowed whole like spaghetti, the prey is further processed by a masticating stomach.

It is interesting to note that the eyestalks retain some form of independence, similar though not to the same degree as the arms of more classic trichordates. While looking for prey, usually one eye faces forward to focus, while another one surveys the area. Unlike the arms of the hortax, these do not alternate in their tasks but seem dedicated to their roles, though with variation between individuals. In other words, some sortax are right-“handed”, while others are left-“handed”. It would be interesting to further study if the rest of the nervous system has also retained a degree of decentralization or has instead undergone more streamlining during bilateralisation.

Since its discovery, it has been recognized that many strange problematica found across Mars are likely relatives of the sortax, something substantiated by recent molecular analyses (Schaf 2337). This likely monophyletic clade has been named Furchordata and is now largely recognized as a distinctive class among the Trichordata. Trichordates, due to the shape of their cloaca, leave behind peculiar trilateral excrements, which in Furchordata specifically get twisted into strange spires due to their more complex guts. Coprolites of exactly this shape have been found in Middle Athabascan sediments, indicating that furchordates first emerged shortly after the End-Cydonian mass extinction event (Brot 2339).

References:

• Busch, Briegel: Marsgeschichten und andere tolle Sachen, Berlin 2338.
• Brot, Bernd: Mist. Die Ultimative Enzyklopädie, Beck 2339.
• Schaf, Tchili: Testing the Furchordata hypothesis using sequenced Martian genome data, in: Current Astrobiology, 465, 2337, p. 13 – 23.

Zitharta

How terrifying it would be if such an object were to loom above the White House, its gigantic hull casting a deep, dark shadow, its jet-engines droning with an ear-shattering noise and its tentacles quivering in anticipation of grabbing up some hapless humans. Thankfully though, the Zitharta is not an alien spaceship coming to invade Earth, but a small, harmless aquatic animal, only as tall as a thumb!

The zitharta is an enigmatic arezoan, for a long time wrongfully classified within the waste-basket taxon “Brachiostoma”, solely due to its tentacles. By the looks alone it is apparent that this animal’s anatomy is a world apart from most other arezoans. Its body consists of a main mantle, somewhat shaped like a professional bicycle helmet worn at the Tour de France. It is what holds all the internal organs and is supported by a siliceous endoskeleton, not unlike a glass sponge. At the front is a frilled mouth with two fan-like tendrils, which the zitharta uses to capture food particles and small prey out of the water. Above the mouth is a three-rowed series of small ocelli, each one coming with its own eyelid, which sometimes configurate into amusing expressions.

Most conspicuous about the zitharta is of course its “mast”, a long, rod-like appendage that grows underneath the mantle. The “mast” is supported by a sturdy biosilicon rod and hinged at its upper end. On it grow ten pairs of little tube-organs, which, through peristaltic pumping, can create a continuous and coordinated water-flow. This form of jet-propulsion, perhaps the most complex so far encountered in the solar system, is the main method of locomotion of this animal. The two fleshy fins at the bottom end of the “mast” seem to mainly function as steering rudders. An air-filled bladder inside the mantle allows for changes in buoyancy.

Zitharta live in very deep caverns and subglacial lakes of the southern hemisphere, whose waters stay liquid all year round, thanks to the planet’s remaining interior heat. In these very dark environments, they help themselves with a large skin-patch on the posterio-dorsal mantle which houses bioluminescent symbionts. With these biolights the zitharta can navigate their way through the dark waters while also attracting small planktonic organisms.

This is as far as our knowledge on these animals goes. On a drying Mars, these aquatic, subterranean creatures are exceedingly rare and difficult to observe. We do not know, for example, what they do during times of seasonal anoxia, though metabolic strategies similar to other cave-dwellers seem quite likely. We also do not know how they reproduce or what other animals prey on them. Finally, there remains the question of their aforementioned phylogenetic status. After the break-up of Brachiostoma, zitharta have become notorious problematica. They possess a U-shaped gut, with the cloaca emerging right below the feeding tentacles, which has prompted some researchers to place them close to the Antitremata, but the usage of biosilicon is virtually unknown in said phylum and there are other glaring differences. The discovery of the closely related githarta and zotharta beneath the northern polar caps has also not helped the matter, as they still closely resemble the zitharta. Nonetheless, the growing amount of taxa has made some researchers more comfortable with classifying these organisms within their own, distinct phylum Trabsozoa. Micropaleontologists have found the distinctive rods of trabsozoans in ancient chert deposits, indicating that these lifeforms could have already existed when Mars still had oceans.