Yateveo

Winter in the tundras of Mars is desolate and hostile. The flora enters a near-death state, only protected by anti-freezing fluids. Small animals that can only crawl or are sessile enter a deep state of hibernation, hidden underground. The animals with legs wander north to the warmer shrublands. But there is one exception.

The yateveo is a wanderstalk which stays in the frozen wasteland, even though it should be able to migrate like its relatives. But it does not like using its legs much, instead preferring to stay in one spot for most of its life. Yet, despite its sessile nature, it is the most skilled carnivore among its clade. Most wanderstalks capture their wadjet prey by lying valve-open like a venus fly trap, waiting for a hapless victim to land on them, perhaps attracted by pheromones. Once the prey lands, tentacles ensnare it and the valves clap shut. Yateveo does not have that patience.

Its natural weapons are two highly modified arms which can shoot out sharp needles attached to silk-like strings. Biological harpoons. In principle they function somewhat like a multicellular version of the nematocysts of jellyfish. When not in use, the needles sit inside a pressurised chamber, ready to dart out. When attacking, the chamber opens a little, pushing all the air out and the needle with it. Once it has pierced its prey, muscular action retracts the string, reeling the harpoon in. How this organ may have evolved remains a mystery. If it can also regrow if severed is also an open question.

What is known is that this artillery is so efficient compared to its relatives that the yateveo rarely has to change location but can spend most of its life in a single place and simply snipe poor little fliers out of the air. This also means that it can easily accrue enough storage of nutrients and fat inside its stalk and legs that it can easily sleep through the winter, thanks to its low metabolism.

However, there is one occasion where yateveo do get up and walk and that is during the thawed-red summer months where they try to find a mate. During these times, they can rarely be observed hunting on foot, which is quite an odd sight to behold. Combining eyesight, leg-movement and aiming speaks for coordination-skills that are uncharacteristically high for such an otherwise primitive organism.

Badarian Fly

Among the many differences between Earth and Mars is that what can colloquially be referred to as an “insect” is much more straightforward on one planet than on the other. Powered flight has evolved on our planet only four times and only once among the invertebrates, and once the insects made this important step, they occupied every niche available to flying animals their size. In contrast, the organisms that an average layperson might refer to as “Martian insects” can come from vastly different backgrounds, attesting to a long forgotten time when the air was thicker, evolving flight was as easy as going back in the water and vast swarms of aeroplankton made up large parts of the global ecosystem. Among the red planet’s small to microscopic flying organisms, one may find wadjets, the larvae of shellubim, spring-tailed furchordatans and even hummingbird-sized ballousaurs and pedicambulates, which parasitically feed on the blood of larger Martians. But most prominent (behind the wadjets and aeroplanktonic larvae) are the nekhbets, a group of tiny archaeocephalians.

 

 

Most iconic of this group, for it is encountered the most across the Martian shrublands, is Paradipterosaurus ranamusca, commonly known as the badarian fly. In it we can also observe the basic bodyplan of this clade, though it has become quite abstract in more derived members. As we can see, having evolved from a six-legged ancestor (perhaps an early stultusaur or maybe even something more ancient), nekhbets developed a unique arrangement wherein the front and back limbs became wings while the centre pair retained their walking function. The spine between these sections is largely stiffened and inflexible. As with the ballousaurs, who evolved their wings out of their hindlegs, this seems quite silly at first. One would think that the “draconic” configuration, wherein the middle-limbs become the wings, would be easier and more practical to evolve, but observation has shown that this four-winged form comes with many advantages which allows the organims a stable, controlled and flexible flight, somewhat akin to what is seen in some man-made drones. Indeed, it seems to have been a winning strategy, for the only “draconic”-winged onychognaths were a short-lived group of tagmasaurs that went extinct at the end of the Isidian, while nekhbets thrive until modern day.

The badarian fly buzzes through the shrublands, its long neck curled up and its legs tucked in, using its painted tail for manoeuvring while on the search for succulent young fractarian fronds. When found, the beetle-sized animal uses its tiny cheliceres to gnaw into the “plants”, feeding on the soft, jellicious tissues and sucking up any available liquid. A single fly is often too small to cause significant damage, but in groups or swarms they can become a serious threat to the organisms’ health. Many fractarians have thus evolved defences against this and other small, flying herbivores, such as bristles, hardened cuticles, deadly toxins, suffocating sap or even venomous needle-hairs. Some arephytes, who may also fall victim to this pharaonic plague, have gone one step further and became carnivorous, much in the fashion of the sundew. With the spongisporians, the badarian fly and other nekhbets share a more positive relationship. They will often inhabit the porous bodies of these sponge-like organisms, perhaps feeding them in turn through their excrements.

The badarian fly is among the many areozoans who annually migrate to the great tundra in the south, when the summer sun thaws the top-layer of the permafrost and makes the red fronds spring back to life. Although practicing internal fertilization, most nekhbets lay their unshelled eggs in the spring bogs and ponds that form here, similar to other archaic onychognaths. These eggs hatch first into eel-like larvae, feeding on microscopic water-flora, which then grow six long, webbed, almost frog-like limbs. As they mature, the external gills in the armpits of these "tadpoles" invaginate and become book-lungs. The webbing on the front- and hindlimbs stiffens into a tough membrane, while it disappears on the middle pair. Eventually they crawl out of the drying bogs and fly away to the north. While Haeckel's old axiom of "ontogeny recapitulates phylogeny" is not as true as we once thought it was, we may glean from this metamorphosis an insight into how these extraordinary onychognaths may have evolved in the eldest of days.

Southern Ptannu

Despite their unassuming appearance, which recalls wingless fowls, bennus are a quite successful group of organisms that has managed to adapt to all climate zones of Mars. One branch of this family is the cold-adapted ptannu (Bulbornis australis) which inhabits the vast tundra that stretches over much of the red planet’s southern hemisphere.

Though superficially similar to the bennus of the shrublands, the ptannu has a much more bulbous body, denser fur which extends all the way to the toes and extended tail bristles. It is also capable of completely retracting its neck into its shell, including the beak. These are all obvious adaptations towards conserving warmth, which it obviously needs for living in such a bleak landscape. Notably, the auxiliary eyes of the ptannu are much more developed than in other nothornithes, resembling much more the primary eyes atop the cranial bulge.

The life of the ptannu is strongly tied to the seasons. When the first rays of the spring sun begin to thaw the top-layer of the permafrost, the marsfowl migrate south from their winter homes back into the southern marshlands and bogs that start forming. Their characteristically white fur begins to molt and is replaced by brownish to reddish hair which helps them blend into the environment. As the ecosystem, reawakens they start feeding on what they can: Small frondlets, sporians, filulithophore-sprouts, young wanderstalks with unhardened shells, wadjet larvae, as well as tachmut and smaller onychognaths. Once the short summer begins, the ptannus enter breeding season.

Here it is fascinating to mention that ptannus are among the few Martians that can be described as good parents. When two single ptannus meet during breeding season, they usually mate for life and build a nest out in the open tundra which they protect together. How the pair of monogamous hermaphrodites determines who has to be the “mother” in the family, as in the partner that is  impregnated and has to produce the eggs, is not known, though some pairs have been observed changing their roles each season. After a few weeks, the two to seven eggs hatch into precocial young that are immediately able to follow their parents around. The parents care for them greatly, teaching them how to feed and warming them with their bodies during the cold nights.

Unlike some other tundra dwellers, ptannus do not immediately migrate north with the onset of autumn, but choose to remain for a few more months. Their fur turns white to blend in with the growing snow and the family exploits the few remaining resources that have freed up now that everyone else has left. Only during the worst parts of winter, when photosynthesis crawls to a complete halt and makes it difficult to breathe in the tundra, do the ptannus migrate northwards towards oases in the shrublands, which they seem capable of finding by pure memory alone, perhaps using certain landmarks for orientation. Their children follow them and memorize their paths, until at the end of winter they have grown mature and begin living on their own.

It was originally thought that the southern ptannu was closely related to the northern one (Bulbornis borealis, though read on), which inhabits the much smaller tundra surrounding the north pole, and that they formed a single genus. One of the first ever molecular studies done on Martian organisms has however cast serious doubt on this, finding evidence that, surprisingly, the northern ptannu is actually more closely related to the highly aberrant marsalk of the northern ice cap (Leidy 2322). This makes these two an obvious case of convergent evolution. Since the northern ptannu neither belonged to Bulbornis anymore nor was close enough to be shoved into Areoalca, it has since received its own genus, whose name has now been agreed upon to be Paraxenoalca.

References:

• Leidy, Dustin: Molecular evidence disproves ptannu monophyly, in: Nothornithology Bulletin, 14, 2322, p. 76 - 93.