Spiny Gilleylowe (second picture by u/M4theus4rts)

Kingdom: Animalia

Phylum: Chordata

Clade: Eugnathostomata

Clade: Acanthodii

Class: Coelospondyli

Subclass: Polydonta

Order: Daeognathiformes

Family: Daeognathidae

Genus: Guailong

Species: G. htaahsingkaalensis (from Mandarin 怪龙, “strange dragon of the Htaahsingkaal Plateau”)

Temporal range: Jartunian to recent (5.6 million Vuleto years [roughly 14.4 million Earth years] - present)

Information:

When the intelligent alien race known as the Eos created Universe-895, fleeing the destruction of their own universe, they sought to bring life to a virgin universe, seeding each world with the necessary organic molecules and compounds needed to jumpstart abiogenesis. While these procedures succeeded on some worlds, they found that for as many worlds that successfully produced life, there were just as many which had not, and far fewer which produced sapient life. This was when they would launch *Khau Tsvoa'oodhh-ptaach* (IPA: /kʰaw t͡svoaʔoːðː ptaːt͡ʃ/), or Project Universe Seed. Project Universe Seed started with the creation of an island chain called Archaeonesia encased in a pocket dimension in the deep oceans of Precambrian Earth, using the uniquely extreme and isolated conditions of the archipelago as a way to incite an evolutionary arms race and eventually force intelligent life to evolve, continually seeding the island chain with lifeforms from all throughout Earth’s geologic history. From there, candidate species would be selected and genetically modified before being placed in similar “petri dish” environments created on other planets, inciting further genetic and evolutionary divergence within the specific confines of this new planet’s conditions. Other planets which yielded life from abiogenesis procedures were also subjected to similar experiences, being given their own equivalents to Archaeonesia as a testing ground for early lifeforms before they would be genetically modified and seeded on other planets. On some planets, Archaeonesian-derived lifeforms and lifeforms derived from abiogenesis procedures on other planets would even be mixed within the same environment, the idea being that in the face of new competition in an unfamiliar environment, this would provide further ecological strain and force the native lifeforms to become more creative with how they adapted to their new homes. Because of these procedures, most life on planets nowadays is either remarkably similar to Earth life or utterly and truly alien, with a great many planets sporting silicon-based lifeforms living alongside carbon-based ones. To manage their experiments from afar, the Eos would create an advanced AI system which fully automated the environmental and ecological processes of each planet and, in particular, each isolated island chain which served as a testing ground for life which would later be seeded across the entire planet in various waves. During the Permian epoch, they would seed life from the original Archaeonesia experiment (as well as an experiment on a planet called Throng) on a Uranus-sized exoplanet called Vu’ulen (Vuleto: /vuʔulen/).

Notable for the fact that it orbits a sun which emits infrared radiation, Vu’ulen’s sky and landscapes glow a vibrant red, its vast oceans tinted maroon. With slightly lower gravity than Earth, fliers on Vu’ulen can get substantially more bulky than they would on Earth. The entire planet is in the middle of a hothouse era, with permanent ice sheets only occurring at the farthest extremities of the poles and large tropical storms being common along the coastlines. Two major continents, a northern continent named Hlaahtto (Vuleto: /ɬaː.θːo/) and a southern continent named Tahzzugi’i (Vuleto: /taʒː.ug.iʔi/), make up the majority of dry land on the planet, with several smaller subcontinents and large island chains along the fault lines. On Tahzzugi’i, high up in the velvet steppes of the Htaahsingkaal Plateau (Northern Sungnap: /θaː.ʃiŋ.kaːð/), a peculiar lifeform descended from the Archaeonesia seeding glides across the alpine winds: Guailong htaahsingkaalensis, the spiny gilleylowe.

Despite its seemingly reptilian appearance, the spiny gilleylowe is actually a member of a far more peculiar lineage: descended from a clade of terrestrial vertebrates called coelospondyls (class Coelospondyli), it’s actually a highly-derived acanthodian, descended from a Brochoadmones-like ancestor. This makes the spiny gilleylowe a closer relative to sharks, rays, and chimeras on Earth than to any proper tetrapod. Originally a dominant clade back on Archaeonesia, the introduction of amniotes quickly spelled disaster for the clade, leading to the complete extinction of larger-bodied members of the clade while the survivors were relegated these animals to small, generalist niches. However, on Vu’ulen, where the only other vertebrates are largely relegated to small herbivore niches by the presence of silicon-based lifeforms dominating large herbivore and carnivore niches, the coelospondyls were able to proliferate into small-to-medium-sized predator niches on the southern continent, filling a niche akin to that of small canids on Earth. On Earth, the spiny gilleylowe would be far too large to fly, reaching between 4-6 feet in length and between 15-30 lbs on average, yet Vu'ulen's lower gravity allows this rather bulky animal to coast on the wind currents for several miles at a given time, climbing up and throwing itself off of high ledges to gain lift. 

Though this creature’s names in the native Vuleto language, xuu’ (Vuleto: /xuːʔ/, “biter”) or hlaa'-thi'-phooht-unu-iig-xu/hlaa'thi'phoohtunuiigxu (Vuleto: /ɬaːʔ.tʰiʔ.pʰoːθ.unu.iːŋ.xu/, “[the] creature which kills with one bite”), indicate a deadly nature, this creature is not known to be aggressive towards most sophonts, though it is known to approach them in groups out of curiosity much in the same way seals and dolphins will approach and attempt to play with humans. While it is indeed venomous, with a potent hemotoxic venom capable of killing animals up to the size of a small elephant, these creatures only rarely bite, preferring to either flee or swing their spiny tail in front of them and hiss aggressively as part of a threat display when confronted with danger. It will only bite if cornered, injured, or aggressively handled. Their otherwise docile nature and so-called “ugly-cute” appearance has made them a popular pet amongst the native Vuleto species since time immemorial, with ancient cave paintings depicting the two species hunting together. Its affectionate nature when hand-reared from birth and ease to train have earned it the moniker of the “Vuleto skydog”, and it is amongst the most popular animals in the intergalactic pet trade. In fact, the Northern Sungnap language, spoken in its native region of Vu’ulen, refers to the creature by a far less intimidating moniker because of the close association between the Northern Sungnap ethnic group and the spiny gilleylowe: ìíghhilxwááhthsòtnááuuhlxhààdrìíng (/ìíɣ.hil.ʍáːθ.ʃòt.náː.uːɬ.χàː.d̠͡ʐìíŋ/), or “(the) one who sails (the) sky at dawn”.

Though adapted for mountainous terrain, primarily inhabiting karst mountains and cliffs, these animals appear to do moderately well in montane forest environments as well, being found at lower elevations in smaller numbers. A largely nocturnal/crepuscular animal, they sleep under trees and large boulders during the day before emerging in the evening/night to forage and socialize, migrating in search of food on other mountain tops, their red skin helping them to blend in with the sky and surrounding vegetation. A highly social and intelligent predator, it shows a high degree of convergent evolution with Earth mammals in behavior, having social hierarchies and highly complex family units. These family units typically consist of a mated pair and several generations of offspring. Social in nature, these creatures tend to sleep next to one another and have been observed play-fighting. A highly vocal creature, its long, whooping calls can be heard from miles away, a way of marking its territory to other spiny gilleylowes. Shrill hissing and loud shrieking are also reported vocalizations, the former an expression of agitation and the latter a vocalization in pain in addition to a call of excitement. Primarily a sight predator, it is able to see infrared light (as per its planet’s available light rays), visible light, and ultraviolet light. By contrast, its hearing is significantly less advanced but still passable. Though it has one set of true eyes, two pairs of photoreceptive “proto-eyes” can be found on one side of the main pair. What evolutionary pressures led to this animals developing tube nostrils is unknown, though it has been suggested that its lineage may have briefly returned to an aquatic or semiaquatic way of life at some point before switching back to land, which would explain the underdeveloped digits on its frontmost pair of limbs.  The function of its long, backwards-pointing tube nostrils is not exactly known, though it is suspected to potentially aid its sense of smell. 

Spiny gilleylowes are simultaneous hermaphrodites and mate for life, courting one another by chasing each other through the mountain tops and divebombing each other. Spiny gilleylowes are simultaneous hermaphrodites and mate for life, courting one another by chasing each other through the mountain tops and divebombing each other. Once on the ground, whichever one manages to overpower the other is the one who penetrates, mating occurring either with one individual on their back or with the tail pushed to the side. Gestation takes roughly 5 weeks before the eggs, which are amniotic in nature, are laid in a den situated between boulders or inside the refuge of a cave, the young hatchings, as many as 10 to a clutch, in 4 weeks time. Young spiny gilleylowes, called pups or nuggins, are born blind and deaf and are like this for the first 2 weeks of life. Dependent on their parents for the first 2 years of life, some youngsters may leave their family behind and form their own family group at 2 years old, when they’ve reached physical maturity, while some will stay behind with their family group. By age 3, they will be old enough to rear young of their own. By age 4, they will have gained their adult coloration, being born completely pink.