Syncarpus

 
Thecocerates such as Cecrops are widespread across Mars, though mostly restricted to warmer regions usually above the 0 or 10° C-isotherm. Syncarpus sarahlandryi is the only known living exception to this, as it is found in the milder shrubland regions and during the summer thaw may even follow other migrants into the tundras.

Although not a true ectotherm like its northern cousins, it is not a homeotherm either. During the warm summer months and days, its metabolic rate is largely the same as that of relatives like Cecrops, strongly influenced by the temperature of the environment. But during winter, when it hibernates in dug-out burrows left behind by shetaw, its metabolism raises its body temperature notably above that of the environment. The same happens also when Syncarpus forages in the cold Martian nights. Such metabolic variability is on Earth only observed in a few reptiles such as tegus and pythons, though it seems widespread in Deltadactylia outside of the Thecocerata. It likely evolved as a compromise to handle the often extreme temperature changes throughout the year on the one hand and general food scarcity on the other.

Likely for the purpose of insulating its temporarily heightened body temperature, Syncarpus is also the only thecocerate that is not naked, but instead covered by an insulating integument. This integument is a plumage of frilled scales, very similar to what is found in the Banuptet and some other deltadactylians. It is possible that this is homologous, meaning that Syncarpus is a relic of a more ancient radiation with all other thecocerates having lost this trait. On the other hand, overlapping scales seem to be ancestral to the deltadactylian clade as a whole, so this may have just been an adaptation that evolved multiple times independently through parallelism. Skin data from fossil thecocerates is unfortunately lacking, leaving this an open question (Sivgin 2345). Interestingly, during ecothermic metabolic phases, Syncarpus uses little muscle fibres at the base of each feather-scale to raise them up, breaking the insulating effect to better allow environmental warmth to reach its body. During mating displays, where these hermaphroditic aliens determine who has to bear the young, this ruffling is also used to intimidate the partner into a submissive, breedable position.

Syncarpus usually gives birth as a single parent to two or three live, though underdeveloped, young in their burrows. Curiously, only one young per litter is lavishly fed, while the other siblings are neglected and have to fight for scraps. Once the spoiled child grows large and strong enough, it eats its weakened siblings, well within the parent’s wishes it seems. Likely the siblings only exist as failsafes in case should the favoured child die and otherwise are just a form of food storage, much like how on Earth some birds and frogs produce excess chicks and tadpoles as cannibalistic food rations. For this, Syncarpus has, rather morbidly, been given the nickname “Martian Curate” in some Terran books (see Grauel 2323 for an egregious example), in clear reference to the Synthologist Cult Massacre on the International Lunar Station. I strongly disapprove of such naming practices, as it needlessly demonizes these organisms and makes light of a truly horrendous tragedy.

References:

• Grauel, Trant: Martians from A to Z. Astrobiology explained for Kids!, New York 2323.
• Sivgin, T.K.: Life on a Dead Planet. The first 3 billion years of Evolution on Mars, Zürich 2345.

Cecrops

The Deltadactylia are a quite varied group of three-limbed onychognaths. Some walk on all three limbs, forcing them to a rather awkward gait when ambling about but also allowing them a fast, bounding gallop when running. Others have given up such restrictions by becoming bipedal, turning the “great appendage” at the front into a proper arm with a grasping hand. These Martian bipeds are often grouped together into the clade Goniopoda, named after their angled ankles. A prime member of this group, often encountered in the vast desert regions of the planet, is the Cecrops, which itself is often classed in the subgroup of the Thecocerata.

Herein we see a prime example of a small carnivore of even smaller game, which has been shaped by the relentless planet into a downright mischievous opportunist. Long legs and broad feet make it glide over the sands and with large eyes and alert antennae it scans the desert for any source of food and water. A long arm with dextrous fingers grabs anything it can catch. A striped pattern along the flanks and flat back make it blend in with the wavy, low-gravity-formed dunes. Giving the Thecocerata their name are little keratinous hornlets growing underneath the mandible (which, if you remember, is the upper jaw in these organisms, not the lower one as in Earth vertebrates), which have likely evolved in lieu of true teeth that these onychognaths either lost or never developed. In Cecrops the pseudoteeth have curiously been reduced to just one large hornlet, though this seems to be enough to kill various smaller prey, such as ifrits and hortaxes, or to crack open armored animals like dust slugs or the kratox. Another defining element of the Cecrops is the strange ornament growing atop the mandible, which is a horn-encased bone that spans between its tips a little sail of coloured skin. It is likely used in some form of social display, though how exactly has not been observed so far.

Though somewhat dinosaurian in anatomy, the Cecrops is far more like a large lizard in physiology and behaviour. Almost all thecocerates are ectotherms through and through and only capable of standing upright on erect legs because the low gravity of the planet makes this posture far less energetically demanding for a cold-blood. We see something similar repeat in the Yrp, which is not related to the goniopods, but has certainly evolved along similar lines. Even then, the long, lizardine tail is often used as a prop to stand on and is even sometimes dragged across the ground while walking slowly, leaving characteristic trackways in the sand. As expected, thecocerates also spend much of their mornings bathing in the sun and become sluggish when exposed to low temperatures. During droughts and winter time they endure through brumation or aestivation. Though this physiology seems archaic, such low maintenance metabolisms seem to be a winning strategy on a planet that is depleted in resources and oxygen, for thecocerates are widespread and diverse across most of the warmer regions of the red planet. The exception to the rule is Syncarpus and possibly some fossil members, which were large enough to have been mesotherms simply by virtue of their body mass.

Cecrops in size comparison with a mostly human astronaut.

Cecrops has a less than stellar reputation among the people of Mars. Though too small and weak to be a threat to astronauts (thanks to Earth’s higher gravity gifting us with stronger bones and muscles, we humans could probably kill such creatures with a single good punch if we wanted to), their curious and mischievous nature during their searches for food has led to many complications, among them infamously being accidental damage to the external cables of an ISRO research station. Though the cable-biter died from an electric shock, this led to a complete system failure that made the vyomanauts inside suffocate from carbon dioxide in their sleep. Another factor is probably also just their appearance. In most onychognaths, the eyes reflect the sunlight in such a way that the shine gives the impression of pupils, making their faces more approachable. In the Cecrops, however, the eyes are of such a mat nature that they expose these organs for what they truly are: Cold, black, glassy beads, like a doll’s eyes…

These animals are also a nuisance to other inhabitants of Mars, as we see in the first image of two Cecrops opportunistically feeding on the nest of a rannu. Cecrops themselves do not have to fear egg-thieves, for deltadactylians give live birth. Truly enjoy this advantage, they cannot, for their plunder on others is only lucrative until the parents come back home.

Wadjets

Wadjets are the flying members of the larger phylum Aspiderma (which also includes aquatic relatives and limbless worm-like varieties). They are best described as Mars’ closest analogy to the flying insects of Earth. Like them, they are completely covered in an exoskeleton and fly with outgrowths of said skeleton. That is largely where similarities stop.

The cuticle and exoskeleton of wadjets is for example not made of chitin, as in arthropods, but instead of a material called tunicine, which is also used by a variety of other Martian organisms, such as the Antitremata or the chirorbites and other fractarians. Tunicine may sound like an exotic material, but is simply a more specific descriptor for cellulose when it is produced by animals instead of plants. On Earth, tunicates are the only animals that make use of cellulose, hence the name, while on Mars it is a quite common building material for the fauna. This seems strange at first, seeing as how chitin and cellulose are very similar polysaccharids, though the devil is always in the detail. Unlike cellulose, chitin requires nitrogen for its production, of which Mars is naturally starved of. This makes it clear why tunicine has replaced chitin on this world.

The wadjets’ head structure is also rather unusual, as can be seen in the above illustration of the Sirek. It consists of an often elongated segment made up of various hardened plates, resembling somewhat the head shields of prehistoric agnathan fish. Most striking is the main eye plate which in most species points straight forward above the mandibular jaws, almost like a pair of goggles. On top of the head are more eyes facing up, possibly to detect flying predators or changes in light and weather. Instead of tracheas, wadjets breathe through gill-slits embedded in the ventral skull-plates, which lead to complex book-lungs. The jaws of wadjets consist of two or more mandibles right beneath the main eyes, which open horizontally in some species, vertically in others. The six  to eight beady eyes of the wadjets are not compound eyes, but primitive, liquid-filled lens-eyes, not unlike those of you and me (though instead of having eyelids they are just covered by a thin translucent sheath of the exoskeleton). The only other group of organisms on Mars that evolved similar eyes are the chirorbites. Behind the head-piece begin the wings, which usually number six to eight, except in the aeropedes. At the end lies the so-called “telescon”, on which I shall comment later below.

Most wadjets are aerial predators that have adapted towards hunting other wadjets and the flying nymphs of shellubim, as seen here with the Athlit. This species even evolved a sort of “nosehorn” for this purpose, which it uses to disorient and stun flying prey, much as a marlin does with fish. Larger species of wadjet also prey on ballousaur onychognaths and even smaller members of the flying tripod periostracans. There are of course also non-predaceous members. Most of those feed on the sap of softer fractarian flora with specialized mandibles which can cut through the cuticle and suck the organism dry. Unsurprisingly, some groups descending from these herbivores have come to utilize their mouthparts to parasitically feed on larger animals. A few gnawing wadjets have also been reported, which burrow into the trunks of spongisporians much like worms into an apple.

Though wadjets are found in nearly all regions of Mars, the reproduction of most is heavily tied to the spring thaw in the southern and northern tundras. As the permafrost does not allow it to trickle away, the meltwater accumulates into shallow, stagnant bogs and ponds into which the masses of migrating wadjets lay their eggs. Their young begin life as worm-like aquatic nymphs, similar to more primitive aspiderms found at the poles and underground, which gradually grow their wings out of what appear to be external gills at the back. At the height of spring, these fly out of the water and feast on the abundant shellubim nypmhs, the revitalised vegetation and various migrating animals around before following their parents back home once winter freezes the tundra again. Many wadjets have however completely lost their ties to the water and give live birth to fully developed young, sometimes mid-air.

What is peculiar about wadjets is the complete lack of walking limbs, allowing for only cumbersome locomotion on the ground. Some signs point towards this being a legacy of a rather peculiar origin story. Evidence exists that when Mars had oceans it also had a much thicker atmosphere, constantly resupplied by volcanic activity and possibly with average air pressures almost twice as much as on current day Earth (Hu et al. 2015). Combined with the low gravity, this would have made flying feel more like swimming. Various signs from the fossil record point towards the wadjets descending from a marine aspiderm ancestor that, in such a more benevolent atmosphere, evolved flight directly instead of first going through a walking terrestrial stage. Perhaps the wadjets first used their wings (likely derived gills as in their nymphs) to sail across the water’s surface, before learning to glide short distances to avoid predators until eventually gaining fully powered flight. From that point on, wadjets seem to have lived an almost completely aerial life swimming through the atmosphere almost without ever having to touch the ground. This, as microfossils indicate, they did together with a variety of smaller lifeforms that must have formed huge clouds of aeroplankton. This extinct aeroplankton must have bee much more extensive than the poor excuse that exists today on Mars and likely played an ecological role much more like actual marine plankton. Attesting to this is Regnopteryx gigas the fossil of a giant wadjet from eons ago, whose giant, cuticle-enforced wings must have reached larger spans than what was seen in any of Earth’s pterosaurs (Sivgin 2345). It had a unique filtering mouth structure not seen anymore in modern wadjets, which strongly suggests this creature lived like an “air-whale” by feeding on the abundant aeroplankton of prehistoric Mars.

The days of the air whales are long gone. Though the low gravity still assists, the loss of much of Mars’ atmosphere has made flight much harder. The wadjets, with their now cumbersomely heavy exoskeleton, had to reduce much in size to stay airborne and also had to find ways to be more adept on the ground. For this purpose, it seems, they have evolved a telescon, which is not found in most fossil members, who had a simple telson or pygidium. The telescon is a series of tail-segments nested into each other which the wadjet can extend or retract like a floppy telescope. With this extendable tail they can more easily slither on the ground, as demonstrated here by the King Discouraeus. It is what has earned these animals their name, for the deity Wadjet was long depicted by the Egyptians as a winged serpent.

References:

• Hu, Renyu; Kass, David, Ehlmann, Bethany; Yung, Yuk: Tracing the fate of carbon and the atmospheric evolution of Mars, in: Nature Communications, 6, 2015.
• Sivgin, T.K.: Life on a Dead Planet. The first 3 billion years of Evolution on Mars, Zürich 2345.