Nerak Thunderbolts

Nerak thunderbolts (Moranis dominans) – named “Neraks Donnerkeile” in the original German – are peculiar invertebrate Martians first encountered by ESA missions in the Kasei valleys. Their name is in reference to their superficial resemblance to belemnite guards, which in medieval folklore were believed to have been petrified lightning strikes. They also go by the name of “helmetworms”.  

Originally believed to be characteristic of the sloped and canyoned terrains of Tharsis, multiple species of neraks have since been found all across the northern hemisphere of Mars, sticking out of most mesas, buttes and rock outcrops. They are arezoans which consist of two calcium carbonate shells that, together, resemble a rifle bullet or artillery shell. Inside the shell is a tentacled organism with a water skeleton. To open the top, the organism hydraulically stiffens a rod in the body’s centre, which makes the mantle grow not unlike a human erection. To close the shell slowly, it simply deflates, though it can also be closed through muscular action if it needs to be done quickly. The skin of the mantle is scaly like in a snake. The nervous system is simple and brainless, sense organs largely consist of chemoreceptors and statocysts that measure air-pressure changes.

Even more so than the dust slugs, neraks are characterized as mineral-eaters, directly feeding off the rocks they grow on. Usually hidden from view, the bottom of the main shell has an opening for an extendable leech-like “mouth”, which gnaws and licks at the rock, dissolving it with acids and scraping actions from a radula. Inside their guts live various areonts which generate energy through lithotrophy, breaking apart the consumed minerals. Different nerak species can have different types of endosymbiont, allowing them to digest different kinds of rocks. Some oxidize iron, others nitrogen compounds and again others might both oxidize or reduce sulphuric rocks. Being sessile animals with very low energy needs, these rather inefficient reactions are enough for the neraks to make a living. Neraks have a tremendous role in shaping Mars, their eroding actions creating crumbling cliffs and treacherous crevasses. In some areas, they have turned entire hills into Swiss cheese. This aggressive erosion is surely another major source of the constant dust which dominates the planet. Ecologically they are also of importance, being a water source for shell-cracking predators.

Neraks gain water by opening up in the morning hours to fold out their filamentous tentacles into the air, thereby catching any morning dew. For the rest of the day, they usually remain closed, likely for protection. Interestingly, the base of each tentacle has an orifice which directly connects to the gut. While these holes are likely for the purpose of drinking and waste disposal, it has also been suggested that neraks, much like the aforementioned dust slugs, could be using their arms to filter aeroplankton and/or feed on the constant dust in the air. The observation that neraks remain closed during dust storms would speak against the latter, however.

Using the muscular radula with which they scrape at the rock, neraks also drag themselves forward into the holes they create. Once a nerak has dug in so deep that it cannot extend its tentacles anymore to catch dew, it pushes itself out of its hole and tries to find a new surface to dig into. These moves can sometimes be fatal, the nerak failing to hold on to the rock wall, falling down a steep cliff and shattering at the bottom. Sometimes other aliens and even astronauts can fall victim to "nerak-falls".

Despite being commonly encountered, there are two major questions regarding nerak biology that remain unanswered, which are how they reproduce and how they are related to the rest of Martian life. To this day, no juvenile neraks have ever been encountered, nor any adults in the state of mating, spawning or broadcasting. It is possible that, similar to animals like cicadas, neraks only reproduce in very long, punctuated cycles and we have simply not been on this planet long enough to witness such an event. Alternatively, neraks might be simply mating and spawning deep inside Mars, hidden from our view. Or, similarly to the skolex, one of the numerous worm-like aliens that slither about the planet might actually be the nerak larva, simply having gone unrecognized as such.

After the break-up of the waste-basket-taxon Brachiostoma, helmetworms (scientific name: Rostrozoa) cannot be confidently placed anymore in any of the recognized phyla of Arezoa. The possession of a shell has traditionally placed them somewhere close to the proposed superphylum that contains Spiriferia, Antitremata and Conchocaudata (Egerkrans 2169), but this might of course be only a superficial similarity. The fact that neraks possess more than two gut openings has always been intriguing for those who have studied the Multistomia, a phylum of multi-mouthed arezoans which have gone extinct in the Lyotian or Argyrian period. But the first definitive nerak shells only start appearing in the Late Athabascan, leading to a large gap in the Martian fossil record between them and the last definitive multistomians. More radical is the proposal by Krätschmer 2161, which is that neraks are not arezoans at all, but are instead a distinct offshoot of the aquatic conulareans, a type of shell-building fractarian. The presence of multiple gut-openings as well as a hydroskeleton would speak in favour of this. However, neraks do not seem to possess an internal glide-symmetry.

References:

• Egerkrans, Jakob: Morphological and molecular evidence support the Martian superphylum Areoconchia, in: Astronomical Zoology, 231, 2169, p. 57 – 70.
• Krätschmer, Simon: A fractarian origin for Rostrozoa, in: Strate Station Geological Journal, 511, 2161, p. 90 – 121.

Rhinoceros Warhoon

Archaeocephalians come in many forms, one of the most distinctive perhaps being the rhinoceros warhoon (Rambisaurus stamperi). Why it has that common name is obvious. The front part of the cephalon, the rhinotecum, is not just radically elongated, but also curves upward to form a sort of horn. What exactly this horn is used for is unfortunately not entirely known, despite extensive observation of this species. Kirkhope’s most extensive study so far has concluded that the horn serves a solely visual function, being basically a flagpost that the warhoon uses to flap and flutter its antennae from, either as a warning or mating display. Some accounts do, however, mention warhoons using their horns for interspecific pushing-matches, very much like stag beetles on Earth, which is sometimes stated as a fact in pop-science books. But these accounts are purely anecdotal and this behaviour has yet to be confirmed in a scientific context.

Rhinoceros warhoons mainly inhabit the dry slopes and shrublands surrounding the western Tharsis plateau. They are quite hardy organisms adapted for tough times. A large part of their gut is dedicated towards storing water, much like a camel, and their thick hide and osteoderms are excellent at preventing evaporation. They are extreme omnivores, their robust cheliceres allowing them to bite through the hard skin of succulent flora, as well as splitting the bones of any animals smaller than them. On occasion they have been observed lapping up bone-marrow with their tongue or even grinding up certain minerals. Their skin is also thick enough to allow them to feed on the predatory red weeds without being stung by their syringe-like urticating hairs.

Characteristic for the warhoons is a dorsal armour composed of multiple osteoderms, which may serve multiple functions. It obviously provides protection from certain mountain predators, such as smaller ballousaurs, but may also serve as a mineral storage or anchorage for certain muscles. Interestingly, the osteoderms are strongly infused with silicon dioxide. This has been interpreted as a form of protection against UV radiation, which poses a bigger danger on Mars than on Earth, especially at the high elevations that the warhoon lives on, as the lower amounts of oxygen on the planet also mean a weaker ozone layer. Silicon dioxide, in other words glass, is very good at blocking at least UVB rays.

On the topic of siliceous bodyparts, warhoons exhibit multiocully, meaning they have more than one pair of eyes. This is exhibited by multiple different onychognath groups, which could mean that it either was beneficial enough to convergently evolve or may actually be the ancestral trait. The benefit is obvious, as onychognath eyes are solid and are asymmetrically shed and regrown to get rid of scratches. The more eyes one has, the less the vision is impaired during these replacements.

Compared to other Martian animals, relatively much is known about the reproduction of the rhinoceros warhoon, thanks to Kirkhope’s work. The mating individuals determine impregnation through antennae-displays and head-nodding, upon which internal fertilization follows. Warhoons are viviparous and develop multiple uterine eggs, but usually only one or two of these eggs fully develops, nourishing itself on the yolk of the surrounding eggs once it has used up its own. Pregnancy can last up to one or two Martian years, depending on the altitude and availability of food, the warhoon being able to pause the development of its embryos if conditions are inconvenient. Once born, the young are fully developed and capable of living on their own.

Rhinoceros warhoons are often noted for their resemblance to the Antennarhynchi, a group of archaeocephalian tagmasaurs from the Cydonian period, to which the famous Tapinotherium and the Glyptosauria belonged. These likewise possessed an upturned rhinotecum and extensive body-armour, though they walked on erect legs instead of splayed ones and were the size of military vehicles. But this resemblance seems to be entirely convergent, as the finer skeletal anatomy of Rambisaurus shows that it is closely related to modern, lizardine onychognaths like the tynus (Sivgin 2345). Nonetheless, studying the function of the warhoon’s horn may allow insight into how these extinct aliens may have used theirs, as similarity in form likely implies similarity in function.

References:

• Kirkhope, David: Life cycle and Ecology of the Rhinoceros Warhoon, in: Areobiology, 195, 2294, p. 94 – 108.
• Sivgin, T.K.: Life on a Dead Planet. The first 3 billion years of Evolution on Mars, Zürich 2345.

Khonsu and Letox

Ortholitha are a rather minor group of antitrematans, with many, such as the zhor, being primitive, slow-crawling, straight-coned creatures. On the eastern slopes of the giant shield volcano Alba Mons is found an exception to this rule in form of the dove-sized Khonsu. By rolling up their shells into an ammonoid shape, they have become more compact and are capable of walking on erect legs, in some ways converging on their distant nothornithe cousins. But the khonsu’s legs are exoskeletal, like an insect’s.

Khonsu are mountain specialists. Highly developed statocysts in their brain give a heightened sense of balance, while a ball-joint ankle allows for firm, flexible footing across steep slopes. Each chamber in the shell comes with its own air sac, which not only makes the shell lighter but also allows for more efficient respiration in the thin air. To communicate, khonsu can blow air through the whole shell, creating a shrill resonating call that echoes across every cliff of Tharsis. The harsh and long winters they survive by entering a deep sleep, usually sheltered inside caves or under overhangs.

An oddity observed among the khonsu is their behavioural pattern during the summer months. Originally described as cathemeral (meaning their activity follows no clear pattern), it has recently been discovered that their activity actually seems to follow an odd cycle where they are active for four hours and fifteen minutes twice a day (Mess 2339). This does not match up with the daylengths on Mars, but it does with the orbit of its moon Phobos, which flies over Mars so fast that it appears twice a day in the sky. And indeed, khonsu seem to become more active as Phobos rises in the west and go to rest once it sets in the east, twice a day. How, why or even if the moon influences the behaviour of these animals remains to be further investigated.

Khonsu are herbivores which feed on a variety of tough mountain flora, but especially on the aquatic arephytes and fractarians that grow only seasonally during the summer, when the fringes of the glaciers melt and create temporary creeks and ponds. During this time, khonsu become highly territorial of these feeding-, drinking- and mating-spots and are willing to enter fights with each other over them. These fights usually consist of shell-bashing and pushing, though kicking and biting has also been observed. Such fights, as well as the general strains of living in this environment, leave visible marks on the bodies of these animals, which grow by adding a new chamber every year or so to their shell. The older a khonsu is, the more bumpy and irregular its shell tends to look.

It is not uncommon for territorial fights to end poorly for the loser, as they might lose their footing and fall down from great heights or otherwise get seriously injured. Various alpine predators and scavengers therefore observe these fights, waiting to gang up and feed on the victor’s victim. In this case, the spectators happen to be letox, who are members of the Podopterygia. This clade is informally also called “ballousaurs”, after the late W.K. Ballou, to whom these organisms were a special interest. Ballousaurs, descending from one-armed deltadactylians, have developed a unique wing-configuration that has no equal on Earth: They fly with their legs and stand with their one arm. The only thing comparable are the extinct Earth-reptiles Sharovipteryx and Ozimek, but these were merely gliders, whereas Mars’ ballousaurs are fully capable of powered flight, their legs having transformed into pterosaur-like membranous wings. This seems rather ridiculous, though various man-made airplanes follow a similar delta-winged design and have proven quite aerodynamically capable and efficient, so one actually has to wonder why evolution has not produced more such hindwing-fliers throughout our solar system.

The letox certainly come by quite well with their bizarre bodies. These are opportunists who, in short soars, scour the mountainscapes and beyond for small animals and carcasses to feed on. On some occasions they have been observed actually agitating two khonsu into a fight, which implies at least some degree of intelligence. Letox usually live in mated pairs that raise a litter of chicks during summer. The babies are born live, though quite underdeveloped, possibly because the wing-anatomy constrains the size of the pelvic canal. The parents thus care greatly for them in their nests, feeding them until their insulating frilled scales have grown and they are capable of flying on their own. For this purpose, both letox parents are capable of producing a form of “crop milk” that is secreted inside their throat and dripped into the chicks’ mouth.

References:

• Mess, Ingo: Biologie und Naturgeschichte der Ortholithen, Hamburg  2339.

Wanderstalk

Striding on its roots

There comes the Wanderstalk,

not wearing any boots.

It does not like to talk

It is not yet a plant

And neither a zoon

It trotted on top of the sand

Which it liked to grow on.

Striding on its roots

Thereon, as stiff as a balk,

not wearing any boots,

there goes the Wanderstalk.

- Müslüm Zohra, Martian Poems, 2285.

When first approached, wanderstalks may appear to an unwary astronaut to be ordinary species of shellubim. They are seemingly sessile organisms, or “planimals”, firmly anchored into the ground by long stalks. Their soft body is protected by a hinged shell, out of which they extend eye-stalks and leaf-like fleshy wings, which photosynthesize enough to fuel the organism’s resting metabolism. But when startled, these organisms have a trick up their sleeves that their sessile cousins lack. They can simply emerge out of the dirt and walk away on crustaceous legs. Wanderstalks are in fact not shellubim, but terrestrial relatives of the amstiels. Most fossil and genetic evidence suggests that they represent a second invasion of land by this basal grade of antitrematans, with endosymbiotic photosynthesis in both being a case of convergent evolution.

And it seems the wanderstalks may be slowly winning their race to land, for they are far more widespread and numerous than the shellubim. They can be found in nearly all habitats, though are especially common in the southern highlands and other elevated regions, whereas shellubim are only common in the northern lowlands and the Hellas Basin. The most likely explanation lies in the atmospheric development of Mars. Shellubim are sessile as adults and reproduce through pollen-like gametes and small mobile larvae which fly or even freely float in the air as aeroplankton. As the fossil record of these organisms suggests, this used to be a very successful strategy early in the planet’s history due to its low gravity, but as global air pressure declined, staying airborne became increasingly difficult, hindering reproduction and also leading to a large decline in the aeroplanktonic ecosystem that adult shellubim fed on. Thus, they are now largely restricted to lowland regions, where air pressure remains higher than average. Wanderstalks meanwhile remain mobile and grounded their entire life and reproduce directly. Much like their aquatic relatives, two individuals simply walk up to each other and mate. The developing young are then either deposited as eggs into the ground or are carried inside the parent’s body, but in both cases come into the world as miniature adults able to walk and live on their own. It is likely that the even more numerous skolex evolved their particular mode of reproduction for similar reasons.

Wanderstalks also do not rely on microscopic aeroplankton to feed. Their eye-stalks double as muscular tentacles, in some of the larger species are strong enough to break an astronaut’s finger (yes, this is based on someone's personal experience). Through a combination of bright colours, foul stenches, sucrose secretions and/or even venom, wanderstalks attract, grab and kill smaller wadjets, which they feed on inside a closed shell, using a pair of mandibles comparable to what is seen in the zhor. In at least one reported case, a yateveo was even observed feeding on the proboscis of a poor ptannu (a tundraic species of bennu) that had unwisely stuck its beak into the wanderstalk’s shell.

Wanderstalks also have the advantage of migrating towards suitable habitats when necessary. Most of the ones living in the tundraic southern highlands in fact do, following the wadjet swarms into the northern shrublands and the Hellas Savannah when winter makes the South nearly uninhabitable. The intriguing thing about this is that they migrate in remarkably straight paths, suggesting they have an innate sense of distinguishing between north and south. How they do this is not yet known. Mars has no global magnetic field which these organisms could exploit in the same way as migrating birds do on Earth, only localized hotspots created by magnetized ancient crust.