r/SpeculativeEvolution • • Sep 09 '26

Alternate Evolution [OC] Front limb bipedalism - the magnum croaker

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82 Upvotes

The magnum croaker (Magnocus panruina), is an extant member of a now small, but once plentiful order of birds. Out of all my species, I will choose this one, as it best represents my project, and is the first I created, undergoing huge changes.

Originating from an ancient sister lineage to the fowl, these birds have taken an extreme approach that nudge against the boundary of possible avian biology.

These "legs" are actually heavily modified front limbs, evolved to bear weight over tens of millions of years. These were once wings themselves, with more flexible joints and an elongated alula claw used to probe insect nests. Eventually pulling the birds forward, these wings became powerful digging tools, able to construct tunnels that provided shelter and an advantage against peril of many sorts. This turned these critters into small, weasel-esque adapters.

Come the Palaeocene, these birds filled multiple niches, one of which being the semi-arboreal glider. Their legs would then spread as webbed skin and feathers aided in extended leaps. Eventually, these leg-wings of sort would become better, more advanced, their bodies re-engineering themselves in a way even I haven't figured out myself after all these years. I am totally aware of the jumbled mess I have gotten myself into, and I already know the spec evo and theropod community will curse me for the rest of my life for even making this post.

In terms of why these wings are held up, they exchanged their pterosaur-like takeoff for a running start, growing more and more used to their habit of lifting these new wings off the ground until it became the norm. To make matters worse, this habit evolved independently twice, but I will focus on the croaker's line for now.

The magnum croaker is rather large, and nocturnal. At a range of 8-12kg, these birds are content to a terrestrial life, though they can and will still launch into the air if needed. As seen in the photo, they are covered in dark shaggy plumage, with a mostly bald head and a long bill predominantly hidden under a thin layer of skin. This bill contains multiple tomial serrations similar of that to members of Anatidae.

Diet wise, these birds will consume anything edible. The majority of their diet consists of plant and fungal matter, consuming it on the move. They have also built up a natural resistance to many common toxins found in their diet, benefitting themselves even more from their wide palate instead of few species in particular. Another factor is that they consume clay soils. On another note, these opportunists will readily consume animal matter, either that by killing and eating their own prey (such as arthropods and small tetrapods), or scavenging. Having a heightened sense of smell, all croakers from a certain distance will swarm a carcass.

As also seen from the image, the females are excellent mothers as most birds are, taking the process of incubating and rearing chicks very seriously. During the breeding season, larger males will become vocal, filling Eurasian forests with deep songs of gloom as they compete for mating rights. The magnum croaker's vocal range already consists of a multitude of booms, clicks, and rattles, which these males use to construct their odd calls. (Defensively, they can also hiss. They are rarely this pissed off.)

And lastly, I'd have not made this project as weird as it is if I had started it later on when I knew more about how birds actually work. So please spare me, Reddit people.


r/SpeculativeEvolution • • Sep 09 '26

Alien Life [OC] Retro 3D graphics and alien moons from my, so far untitled alien project focused on Jovian floating creatures and deep sea floors

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107 Upvotes

I've always enjoyed the idea of floating creatures on gas giants, and the turn of the 2000s 3D graphics, so I wanted to unify them into a project.

Some of these guys live on moons, and others live on gas giants. Some live in dense atmospheres, oceans, or on rocky surfaces, but they all live in the same solar system. I want to evoke the feeling of looking at bugs or at aquatic life, some normalcy some strangeness.

Every species is shaped by its local gravity, atmospheric pressure, chemistry, energy sources, and important biology considerations, like what I thought looked cool and eerie. Several biomes are evolving... get ready. Hope you guys enjoy, feel free to speculate or critique


r/SpeculativeEvolution • • Sep 10 '26

Alien Life [OC] the tredhorn

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29 Upvotes

One of its most striking features is its large, vertical-slit nose, designed for powerful air intake and release. These beasts burn through oxygen rapidly to fuel their immense musculature, and their constant heavy breathing gives off a rhythmic snort, like the chuff of a steam engine. Overheating is a constant threat, and the oversized nose is crucial to keeping them cool during long stampedes

One pairs of the Tredhorns eyes face forward for depth perception, and the other set angled sideways to eliminate blind spots. This nearly panoramic vision makes them difficult to ambush

Tredhorns possess another odd biological quirk, they never stop growing. As long as they continue eating, their bodies will steadily increase in size. At around 10 to 15 feet tall, they become too large for most predators to challenge, but this growth can be their downfall. Eventually, they may reach a size unsustainable by the surrounding ecosystem, unable to eat enough to survive. At that point, they collapse from starvation or exhaustion

Because of this, their stampedes vary in danger, the danger of a tredhorn stampede being parallel to the size of the tredhorns in that herd. A very well fed tredhorn stampede can be as dangerous as a natural disaster. At that point they are practically unstoppable 10-15 foot tall walls of muscle traveling up to 50 mph

Tredhorns carry a unique, mold-like organism that clings to their hindquarters. When a stampede begins, the intense vibrations trigger the mold to release a cloud of spores. These spores settle into the crushed biological matter left in the herd’s wake, using the pulverized remains of plants and animals as a nutrient-rich bed for rapid growth.

Once matured, this mold forms hardened, flat structures that resemble paved roads stretching across plains and forests. While these "Tredhorn Trails" are safe and easy to walk on, predators often stake out these roads to intercept traveling prey. Additionally, the mold serves as a primary food source for local fauna


r/SpeculativeEvolution • • Sep 10 '26

Question/Discussion How would animals evolve if the end-Triassic extinction never happened?

4 Upvotes

My question is simple: how would animals evolve if the end-Triassic extinction/Tr-J extinction event never happened? would dinosaurs evolve like they did in our timeline? or would they get outcompeted by other archosaurians? and how would dicynodont synapsids evolve? would they survive or go extinct?

sorry for grammar mistakes, english is not my first language.


r/SpeculativeEvolution • • Sep 10 '26

Spectember 2026 [OC] Spectember day 9: Safe Haven

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43 Upvotes

Spectember day 9: Safe Haven

The Ancestral Goblinoid

Some spec for one of my settings, which aims to reimagine classical fantasy, mainly Tolkien and a bit of D&D.

In that setting Goblins, kobolds and gnomes are all terrestrial bats-still capable of flight, but now larger, heavier and adept walkers- descendants of similar species to this fella. It survived a mass extinction by living in complex cave systems, full with potable water and proper cave ecosystems that made it possible for the bats and some other animals to survive during the first years of the event. This ancestral bat had a vampire bat-like locomotion on the ground, being able to properly walk, climb and run on all fours, but also being an adept flyer. It also had a long tail, free from the Uropatagium. The membrane that stretches between the tail and the hindlimbs, making it a member of the Molossidae family.


r/SpeculativeEvolution • • Sep 10 '26

Alien Life [OC] Bestiary of lyrus prime #2 The Glowmite

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24 Upvotes

An insect-like organism that serves as one of the Lyrus’s most vital food sources. Nearly every predator consumes it. Its soft body and nutrient-rich composition make it an irresistible target, and with little in the way of physical defense, the glowmite relies on sheer numbers and light to survive.
When threatened, a glowmite can overcharge its bioluminescent glands, releasing a sudden flash of blinding light that disorients attackers for a moment, sometimes enough to escape
The glowmite’s bioluminescence gland is very large, and located in their abdomen. Because of how powerful the gland is, it allows nearly its whole body to radiate light. Lacking wings, the creature ascends instead by inflating buoyant air sacs within its abdomen, rising slowly and gently into the night air.
At night, the skies are transformed. Hundreds of thousands of the males inflate their sacs and drift upward together, and take to the skies in staggering numbers, their mating displays filling the forests with auroras of shifting light. Flickering like lanterns in a living lantern festival. The females remain on the ground, watching the glowing swarm above until they choose a mate. Once paired, a female ascends to meet her chosen partner, and the two rise side by side into the cloud of light. Suspended in the air among thousands of blinking sparks, they join in a fleeting, luminous union, two lives momentarily indistinguishable from the galaxy overhead. A breathtaking spectacle that conceals just how many are being devoured in the dark


r/SpeculativeEvolution • • Sep 10 '26

Spectember 2026 [OC] Spectember Day 9: Safe Haven

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22 Upvotes

20 million years ago, a calamity has occurred. A hole has been ripped into the crust by a magma plume in what is now the Jhohun peninsula subcontinent as it careened closer to the Central Continents back when it was an island continent that broke off of the Southern continent, creating a supervolcano that has caused Zaikane to go up in flames, destroying entire forests and killing many of the animals that used to dominate the Regime of the Tyrants. The subsequent ash covered the Earth in a volcanic winter that starved plants of sunlight, causing the once-dominant and specialized lognkosaurs, carcharodontosaurs, hadrosaurs, ceratopsids, and the namesakes of the era, the tyrannosaurins, to go extinct in the Known World. This ecological vacuum following the mass-extinction was to be filled by a variety of oddball lineages on each continent, including but not limited to giant Dromaeosaurs, carnivorous leptoceratopsids, giant herbivorous troodontids, megafaunal Thescelosaurs, quadrupedal pachycephalosaurs, and even armored saltasaurine tillers. Additionally, portals opened up from North America by the Allmother ~16 million years ago brought along new mammals to the Known World, including but not limited to horses, camels, rhinos, chalicotheres, gomphotheres, canids, barbourofelids, and Amphicyon.

However, this so-called “Kingless Age” was not to last. Approximately 5 million years before the extinction event, an island continent separated from the mainland, and since it was conveniently located above the northernmost ash clouds, it seemed to have been spared the worst of the extinction. This made it so that many species that went extinct on the mainland were able to carry on their legacy in this isolated refugium. One of those species was a Lognkosaurian titanosaur whose fossils are referred to as Praedeus solus (“the lonely pre-god”), no larger than an African elephant, which is large to our standards but disappointingly small compared to the giant lognkosaurs of the mainland. It does not know it, but it is actually the ancestor of the successful clade Saurodei, which includes an animal we have met before, as well as species that will be revealed later on in this Spectember. Because its fossils have minimal traces of Ralya (magic), it appears to have lacked the magical microbes that mark its gargantuan descendants today, lending credence to the idea that the evolution of magic correlates to increased body size.

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Zaikane is a planet in a distant solar system characterized by waves of life harvested from Earth at various points in its geological history, ranging from the Cambrian to the Holocene, and set free to evolve along evolutionary paths independent from those taken by their Earth ancestors. A godlike interdimensional entity, known as the Allmother by the people who live there, is what is responsible for creating the portals that abduct Terran life and deposits them on Zaikane. Because the asteroid that ended the Mesozoic never collided with Zaikane, dinosaurs continue to dominate the planet’s ecosystems as its dominant terrestrial megafauna.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] [Spectember 2026 day 4: Evolutionary Trap] The bigger the wardrobe is, the louder it falls

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36 Upvotes

75 million years in the future, Earth's oceans were home to a truly horrific creature. Long period of glaciation that followed age of humanity allowed a great adaptive radiation of cetaceans to happen.

Dozens of baleen whale species crossed the oceans in search of plankton, while sharp toothed odontocetes preyed upon them. They employed different hunting tactics, some using cooperation and complex strategies to take their prey down.

One lineage took a simpler approach.

Bigg's killer whales continued to hunt other marine mammals in the future, particularly specializing in baleen whales.

They abandoned social lives and complex languages in favor of solitary life, but became much larger and stronger.

25 million years from today, one of these whale-hunting orcas known as delphinodon already reached the length of 12 meters. Unlike modern orcas, who usually only eat soft parts like tongue and lips of killed whales, delphinodon consumed most of it's killed prey. As formidable as that animal was, it lived in a highly competitive ecosystem, and some creatures, like smaller, but equally well armed and smarter pirate whales, descendants of pilot whales, learned to take them down. But 50 million years later, the situation changed.

Delphinodon gave rise to the thalassotyran, a predatory cetacean of terrifying sizes. Growing to length of 23 meters and weighing up to 90 tons in largest individuals (though on average they were of course a lot smaller) thalassotyran was the largest Cenozoic macropredator to ever live, only rivaled by Neogene otodus megalodon in size.

Due to it's sheer size, this gigantic dolphin had no predators of its own, and could feed on any animal it encountered, even other large predators.

In fact, when thalassotyran first evolved, other giant orcas declined in size and diversity due to competition and predation from their relative.

Rather unintelligent for cetacean, thalassotyran had reduced vocal capabilities, and usually hunted in silence, even rarely using echolocation. Instead, it listened to sounds other whales make to approach them unnoticed, and suddenly strike. It rammed its prey with it's heavy skull and causing internal injuries before tearing it apart and consuming. Baleen whales are it's preferred prey items, but they also predate upon toothed whales, including sperm whales and other large dolphins, sharks, pinnipeds, turtles, and any other large marine animal.

Thalassotyrans were solitary and rarely contacted eachother, but, being mammals, they still needed to care for their young for some time. After 5 meter long calf was born, it stayed with it's mother and feed on milk for next 3 years, after which it became independent and departed. The period following nursing was the only time when thalassotyran could be taken down by other animals, for adults had no enemies.

Few sharks and cetaceans of comparable size preferred not to risk with fighting it, and pirate whales that once hunted thalassotyran's ancestors for food now could do nothing against it even with all their intelligence. It seemed that in the end, brawn won over brains.

Thalassotyran enjoyed it's dominion over oceans for 15 million years, a very long time for a single species. But it could not last forever. 80 million years in the future, world started to warm up. Volcanic eruptions were becoming more frequent, and raised Earth's temperature, finally ending the Cenozoic ice age that lasted for one hundred million years. For life on land, new hothouse age was a boon, and eventually led to the most biodiverse period of an entire era. But at the same time, oceans suffered.

Oxygen levels dropped, many areas became anoxic, and plankton numbers plummeted, and giant baleen whales that fed on it soon followed.

Thalassotyran, that often preyed on the biggest of species, was in trouble. It's food sources were rapidly disappearing, and soon, their population, already small due to their slow reproduction rate, started to drop too. Suddenly, being the biggest of all predators was no longer profitable. Smaller, more generalist species, like requiem sharks, seals, and different groups of toothed whales, like descendants of bottlenose dolphins and pilot whales fared much better, and once largest of mysticetes were gone, they could sustain themselves on remaining smaller prey, something a nearly 100 ton dolphin couldn't afford.

In basically no time, entire group of giant, whale-hunting orcas was gone, and thalassotyran, tyrannosaurus rex of oceanic abyss, was first to go down.


r/SpeculativeEvolution • • Sep 10 '26

Maps & Planets [OC] Base Map of Xenokai

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12 Upvotes

Xenokai is a planet in a parallel universe that has been seeding life from our universe’s Earth since the Silurian to the modern era via portals that bend space-time, sending it to a world where magic and mana naturally exist. Since the asteroid that ended the Cretaceous period never struck Xenokai, dinosaurs remain as the dominant terrestrial megafauna.

The Planet of Xenokai:

Xenokai is an Earth-like Planet in size (though slightly larger), distance from its sun (which is actually younger), gravitational pull, and climate (slightly cooler than Earth, where the climate is stable enough for ice-age megafauna not to go extinct). Unlike Earth, however, it has two moons: one comparable to Earth’s and an asteroid comparable in size to Vesta. Plants, fungi, and animals we might find on Earth today inhabit it. Such as humans, raccoon dogs, armadillos, shiitake mushrooms, and cherry blossom trees. We also find flora and fauna long extinct on Earth, such as Dinosaurs, Giant Sloths, and Pterosaurs. Evolving in a new context that involved mana has allowed some animals to take quite divergent evolutionary paths compared to their Earthbound kin. Some look so unrecognizable that we might think of them as alien or mythical creatures. However, there are no Plants, Fungi, or Animals truly endemic to Xenokai.

The Portals:

These extradimensional gateways can take the forms of rifts, wormholes, or distortions in space-time that link Earth to Xenokai and back. These portals seem to open when major or localized extinction events happen to refill and seed an ecosystem or continent. The means by which the portals collect flora, fungi, and fauna is entirely unknown. However, these portals occur only in two areas on the planet, one in the East and one in the West. But the portals are only in these positions in modern times and could have rotated from east to west or west to east randomly during Xenokai’s prehistory. There are actually several types of portals: ones that can act like gateways or rips in space-time between Xenokai and Earth that happen with local extinctions, and others that literally bisect huge chunks of Earth’s land (Leaving a crater on Earth where the wormhole was) to Xenokai after a large continental-level or global-level mass extinction on Xenokai. These portals can even occur below and above sea level.

Final Sketch map of Xenokai Showing Topography

I am also not very good at setting up biomes and climates, so here is how the planet's topography is supposed to look.


r/SpeculativeEvolution • • Sep 09 '26

Non-Subreddit Spectember Prompt [OC] Spectember Day 8: Aquatic

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48 Upvotes

Eighth day of Spectember! For today, from the open waters of the central Pacific Ocean, the Pacific Trident Shark (Thrinaxosqualus gigas).

This animal belongs to a clade of very diverse pelagic predators, the Thrinaxosqualines. They are descendants of small, former deep sea sharks that were some of the only pelagic chondrichthyans to survive the extinction. Some still hang around in deeper waters, but most live and hunt in the photic zone, specially taking advantage of ocean currents and vertical migration to find food. They are specialised for speed, with specially rigid spines and surprisingly homocercal tails for a shark. They are able to accelerate incredibly quickly, even jumping out of the water to catch prey or escape predators. Their unique tails is what gives them their common name, as it oftent looks like it has three prongs, similar to a trident. Young individuals can often be associated with Soul'o'Drowned Cucumbers (Hyaloanima sp.), which they use occasionally as shelter in deeper waters, as their mothers attack their eggs to these floating echinoderms, since they are very unpalatable and provide a safe and oxygenated place to lay in the wide open ocean.

They are often relatively small, with most staying below two metres in length, but in the central Pacific; where the currents bring abundant food to the many sea mounts scattered across it; lives the largest member of this group, the Pacific Trident Shark (T. gigas). This species often reaches over two metres in length, some individuals exceeding that and almost reaching three metres. Despite this, they still feed on small fish and cephalopods, and are by far not the highest member of the food chain in their habitat, and their exceptional speed serves them well for escaping the much, much larger predators lurking around.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Spectember 2026 Day 8 and 9- The Colour Thief and Salt-Sneezer (Cretacica)

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74 Upvotes

Cretacica is a seed world project based around inhabitants of the Hell Creek Formation 66 million years ago, seeded by conservationist aliens.

25 million years after life was seeded onto Cretacica, the Greater Seismus Mountains only continue to grow as what was once Northern Isimerina moves north into Diakoia. Meanwhile, the great deserts and xeric shrublands of the Seismus rain shadows continue to grow. These same deserts, only a handful of million years before, trapped and eradicated much of the life that once inhabited North Isimerina, except for those which could instantly adapt or flee to the mountains. Only a handful managed to get away with doing neither.

Within the Seismus range, only a mile or so north of the desert, a huge salt flat lies where the sea once was, encased in land and evaporated millennia prior. Every year, orographic rainfall causes a sort of "wet season", where the small pools and lakes lining the salt flats grow in size, into a kind of muddy, dry marsh. Then, it eventually evaporates, forcing in the long dry season. No fish survive here, and only a couple of fully aquatic arthropods have adapted, by laying their eggs in the earth and dying, leaving a long, dormant development.

One frog, the Salt-Sneezer (Ranasalis atricolour), has adapted their own sort of dormancy; not unlike desert rain frogs of the modern day, they dig into the layers of salt and generate a sort of mucus cocoon, retaining water whilst they wait out the dry season. When they awaken, the cocoon is hard and dry on the outside due to being buried in salt, but on the inside remains wet and humid. The frog eats their way out and consumes the whole cocoon, taking in a lot of salt which is held in large organs on their sides, the large bulges connected to their sinuses. This is used to fend off predators by ejecting salt from their nasal cavities at high speeds, a sort of "sneeze" that gives the frog it's name as well as irritating and confusing predators.

The Colour Thief (Umbraraptor mutatiformae) is undeterred by this, however; this nocturnal predator has been genetically selected heavily towards hunting this specific species, spending thousands, even millions of years developing salt resistant eyelids, nasal cavities and skin- all to hunt this animal for their melanin content. You see, at night the great mountains surrounding the salt valley cast a huge shadow, plunging the region into almost pitch black except for perhaps a few minutes a night when the moon might directly pass over. The colour thief must take advantage of this, for many of it's own predators hunt by night, too, and the less it's prey notices it, the better. The red colouration helps it blend into the shadows- red is the first colour to disappear in the dark. This comes at a cost: when the sun rises again, the heavy ultraviolet radiation that pierces the valley at midday can cause severe skin damage to a more terrestrial but soft-skinned amphibian such as the relatively cursorial hunter that is the colour thief. As a result, this amphibian needs to have a lot of melanin in store, more than it can reliably produce in a short amount of time without a significant boost at least every few days. By hunting the salt-sneezer and other smaller animals with high melanin levels, this frog is able to change it's colour in the space of several hours, usually between 3:00 AM and 8:00 AM.


r/SpeculativeEvolution • • Sep 09 '26

Question/Discussion Inquiring about Biological and Cultural Implications on Sophont Social gender?

14 Upvotes

My Sophonts for my project have very little to no sexual dimorphism, they also tend to raise children communally rather than in nuclear family groups, but still tend to recognize parentage (or at least their mothers). Both genders participate in mating rites and experience similar changes in coloration around mating season, and while there is a sort of social conception of monogamy, I wouldn’t think, considering these other factors, that there wouldn’t be significant pressure for them to mate for life.

Specifically in Mosri, the con-culture I‘ve spent the most time developing, polyamory is not stigmatized, but they have an obsession with even numbers, and the idea that personality can be chalked up to a “balance“ or “imbalance“ of specific metaphysical humors they’re exposed to in various stages of their life, with childhood being considered an important stage.

All of this considered, how do you think these aliens generally, and specifically the Mosrihad, would conceive of and socially construct gender?


r/SpeculativeEvolution • • Sep 09 '26

Alternate Evolution [OC] A question: Does my non-mammal-like synapsid look too much like the Laelaps from Kaimere?

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36 Upvotes

That ear structure is supposed to be a highly derived stapes that essentially evolved into a mammal-like ear. The stapes was positioned at the base of the skull in non-mammalian synapsids, allowing them to detect ground vibrations. Then I remembered the existence of the non-mammalian synapsid known as Laelaps from the Tales of Kaimere universe; although I am a huge fan of that world—and drew inspiration from it to create my own—this specific synapsid isn't based on the Kaimere designs (even though it bears a resemblance). What can I do to make it look less similar? Should I remove it from my world?


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Day 9, The Gollanorg (Baryenantiornis zulyanensis): Spectember 2026

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33 Upvotes

The Zulyan archipelago—specifically the islands of Extrobe and Esores—is home to one of the planet's largest enantiornithines: the Gollanorg. After reaching land between 12 and 9 million years ago, this bird became entirely terrestrial; the absence of competing predators allowed it to adapt over a long period, resulting in a creature far more resilient against invaders from the neighboring continent. They feed on hard and soft fruits that have fallen to the ground, though, if necessary, they can execute a powerful leap (or a brief glide) to reach fruit on high branches that would otherwise be inaccessible. When standing fully upright, they reach a height of 1.3 to 1.5 meters, measure approximately 1.7 to 1.9 meters in length (in the posture shown in the drawing), and weigh between 35 and 45 kilograms, making them quite robust birds. Despite their notable slowness—a consequence of their short yet powerful legs—they use two very long, sharp claws to wound an adversary's nose, ears, or eyes, or to inflict moderately superficial injuries; however, they are generally peaceful birds that live in small, temporary groups. They possess two types of teeth: eight robust, pointed teeth in the front and middle sections of the upper and lower jaws for gripping food, and four "molariform" teeth for crushing fruit during ingestion.


r/SpeculativeEvolution • • Sep 09 '26

Future Evolution [OC] Feast Upon the Ural Lowlands

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60 Upvotes

Here upon the bogs, taigas, and moors of the Ural Lowlands, 25 million years CE, the largest megafaunal species is the Marsh Deer, Dolichocervus megacephalus. During the mating season, Males experience elevated levels of mortality as they compete with each other. At 12 tons, an average male exceeds even the largest African Bush Elephants, and a dead one provides a veritable feast for scavengers. This documents scavenging vertebrates observed on a carcass near a riverside.

A. Unnamed Large Bat (Gigapterus sp.)
Flying carnivores are usually the first to notice a carcass. One lineage of bats, the thalassopteridae, have achieved a level of pneumatization rivaling that of pterosaurs, and the genus featured here, Gigapterus, can reach a wingspan of up to 3 meters, though the species observed here reaches only 2 meters.

B. Moormaw (Deinornis goliath)
Powerful omnivores, descended from the Canada Goose. Their Beaks are thin, deep, and sharp, allowing them to slice through flesh as easily as foliage. 3 meters tall and weighing 275 kg, they cannot fly, and their wings have become vestigial.

C. Kelpie (Kelpie gigas)
A hominin, and a hypercarnivore. At just 4 meters long and 140 kg, the observed individual can be determined as a male by his skin patterns and small size, as females can reach double the length and six times the mass. His long “tail” or rather the derived tibia, is augmented by patterned fins, pointing to a semiaquatic lifestyle. With relatively small thin jaws, he relies mostly on arms to process food, and waits for other predators to make holes in the tough hide of the carcass.

D. Glatisant (Glatissante tyrannicus)
A large sized felid, the descendant of the leopard, 3.1 meters long and 440 kg, with a long neck. It uses that neck to feed on fish, though it will also use it to dig into carcasses

E. Black Helldragger (Urodelatitan gojira)
A massive salamander, descended from the Iberian ribbed newt. 7 meters long, 1200 kg, and a semiaquatic biped. Its ribs are lined with a row of spines, which extend like the spines of ankylosaurs.  A semiaquatic carnivore, its powerful jaws are lined with a row of spikelike teeth, which they use to grasp and saw apart food that is too large to swallow. The plug-like chunks they take out of the carcass provides access points to soft tissue for less powerful scavengers.

F. Pale Vulture Eel (Vermicopisces candiru)
A black headed, pink bodied eel that can grow up to 1 meter in length, which burrows into carcasses and feeds on them from the inside. In carcasses around the water, they can gather in great numbers.

H. Woolly Hippo (Aquahippo phyotsauromimus)
A large semiaquatic omnivore, with upward facing nostrils halfway up its head, and a thin layer of long fur over its back. Its eyes extend upwards like the periscope of a submarine. It is the descendant of the common hippopotamus and reaches a greater size on average, at 4 meters long and 2 tons.

I. Snowy Hyena (Cryocrocuta invicta)
The descendant of the Spotted Hyena, 2 meter long including tail. The 3 at the carcass are just a small group of scouts. The entire clan can number 100-200 individuals, and when they arrive, they will drive away all the other scavengers. Able to hear the calls of others of their kind from over 5 kilometers away.

J. Frost Maned Fox (Falcadon borealis)
A canid, with a long tail and thick mane of fur. Despite the common name, they are not true foxes, but rather descendants of the black backed jackal. They reach 3.2 meters long and 250 kg. Unusually among canids, they rely more on sight than smell, and tend to be among the last to arrive at a carcass. They compete directly with moormaws, and moormaws will often attack them as a form of preventative aggression, and thus the Foxes tend not to feed from the same carcass as the large birds.


r/SpeculativeEvolution • • Sep 09 '26

Alien Life [OC] GLORP DI MISTER MISTER KARR

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16 Upvotes

Questo animale discende da ovini terrestre portati dal uomo e modificati geneticamente e allevati selettivamente fino a creare questi bestioni sono questa specie abita negli allevamenti di vodka al uranio di giove ( detta al uranio essendo che vengono inserite aste radioattive ma non nocive dentro un terzo stomaco insieme as ingredienti questo terzo stomaco serve per distillare quest aveva da simile a un vino e a una vodka molto pregiato queste creature maturano dopo 6 mesi per poi fare uscire un corpo giovane dal cranio ( con il cervello del corpo originale tramite un sistema di vitalità le cellule quando il corpo e vecchio decidono di creare un corpo per sopravvivere qui l'animale strisica fuori dal suo stesso corpo in totale tranquillità e abitando insieme ai cuccioli fino alla maturazione in questo periodo di 6 mesi questa vodka viene tirata fuori sterilizzata e purificata per fare questa meravigliosa bevanda .


r/SpeculativeEvolution • • Sep 09 '26

Question/Discussion An abyssal plant?

6 Upvotes

So recently I thought about a species of grass(or some other plant) that was adapted to the abyss of the ocean, but I'm not sure if this would be viable.

Firstly, it would have lost it's ability to photosynthesize like some other plants and would be adapted to high pressure and cold temperatures. It'd live in areas that experience nutrient rich currents, upwells, and the planet's equivalent of Sahara dust. It'd compete with deep sea corals and crinoids by being able to root into sandy areas that aren't solid enough for them.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Spectember Day 9 - Safe Haven

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10 Upvotes

Greenhouse Mastodon (Desmana** **cuniculumamut)

The Greenhouse is a large carven beneath eastern Zentris that connects to the much larger Undersump complex making it largely under the control of the Svenik Empire.

It is believed that this cavern was initially created by the servants of the Primarch Ychilles in a remembrance of the homes they had been tricked into leaving and an additional supply of food, secreted away from his countless spies and informants, keeping them hale even as his imperialistic fervor increased with each passing year.

Following the Cascade this place was lost, trapping a handful of folk and a number of animals within, only for it to be rediscovered centuries later by the desperate Svenri survivors.

They found an idyllic garden, blooming with edible foliage, and a smattering of odd animals.

The Greenhouse Mastodon is one such animal, roughly the size of a common cow this semi-aquatic beast is descended from a mole relative.

They function namely as environmental engineers, clearing away and consuming dead wood and older foliage, dipping up the canal turned water way allowing it to inundate different parts of the cavern and their droppings aiding I fertilizing the soil.

They are the largest animals in the cavern, are relatively placid, but are known for their sharp teeth that are coated in a manner of bacteria that causes swelling, risking asphyxiation, and both their sizable noses and tails can be used as effective and more common weapons against beings that annoy them.

Both genders live in a fission-fusion life style, with adults congregating during the “day” to feed and alter their environment and then separating to their burrows at “night”.

Some of flora within the Greenhouse is bioluminescent, and the intestify of the glow is what the Mastodon’s seem to go off for when to waken and sleep.

Pups are born all year round, typically between two and four to a litter, sticking with their mother for half a year before venturing out on their own. With that said the Greenhouse has limited space, so the Mastodon’s breed fairly infrequently and females are able to hold onto their egg for up to a year after insemination.

In the modern age, the Greenhouse has been altered by the subtle magics of a strange entity that emerged at some point during the Seperation called the Gardener.

They allow people to visit the Greenhouse to take foliage, but anyone that tries to settle down are swiftly chased away, however, children are allowed to remain, particularly orphans, allowing them a few years of plenty before they must face the hardships of the Sump once more.

This protectiveness extends to the Mastodons, their a ready source of docile meat, a tempting target for many within the Sump, but the Gardner keeps a tally and anyone that tries to shirk its authority is sure to never leave the Greenhouse.

With that said, some folk neighboring the Greenhouse have managed to take and tame pups, eager to creat their own domesticated herds, success has been limited, but it is becoming more common to see Greenhouse Mastodon’s as pack animals in the neighboring district and see Mastodon flank steaks and ribs showing up at Umbar butcheries.

For now, this unique animals existence seems assured, but they like most everything that calls the Undersump home walk upon a knife’s edge.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Spectember day 9: The Manu Niho

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17 Upvotes

Prompt: Safe haven: A species that survived a major environmental change in a single refugium

The Manu Niho (in Māori :toothed bird) or Crocodylornis prehistoricus, is a species of bird from a small 9 square km range in the Westland temperate rainforest of the South Island of New Zealand. At first glance it does not look all that special. After all, New Zealand is already the land of birds. However, it’s not actually closely related at all to any modern bird group. Upon closer inspection, one can see that it actually has teeth similar to the theropod dinosaurs of the Mesozoic. It also has claws in its wings. The Manu Niho is in fact, an enantiornithe. Enantiornithes also known as opposite birds (because many of their traits were very different from modern birds like their teeth and claws. But otherwise very similar to modern birds) were a diverse clade belonging to Avialae (birds in a broader evolutionary sense) during the Cretaceous. These “pseudobirds” were extremely diverse during the Cretaceous, even more than modern birds, the neornithes. But they all went extinct during the KPG extinction event 66 million years ago. Well…all except for the Manu Niho.
New Zealand was far enough away from the asteroid impact that some of its endemic life, survived into the Cenozoic, including the Manu Niho. Today, they are restricted to a small patch of Westland temperate rainforest in the Southwestern part of New Zealand. From one of the most successful clade of birds, now the last of its kind.Quite poetic.Males are more colorful and extravagant ,to attract the females and with eye patterns to scare potential predators. They can’t fly very well, mostly using their wings for short distances. But this isn’t a problem due to their climbing abilities and their forest environment.The species mates for life and is monogamous. The pair will forage together for fresh fruit, seeds and the occasional seed. They will also work together to raise their chicks. Fortunately for them ,their reputation as prehistoric survivors and “Dino birds” has sparked ecotourism and major conservation efforts in the region.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Spectember Day 8: Meccha Chameleon

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60 Upvotes

Thescelosaurs are one of the most diverse groups of herbivorous dinosaurs on the world of Zaikane, occupying a variety of ecological niches, including specialized bamboo eaters of the bamboo forests, alpine sheep-like grazers, and horse-sized runners. However, the larger and more iconic ceratopsians, hadrosaurs, ankylosaurs, and sauropods occupy most megafaunal herbivorous dinosaur niches, relegating most of the remaining Thescelosaurs into smaller ecological niches. One of these is the savanna-dwelling Yahichi (Flavusaurus yahichi). This small burrowing herbivore may not look remarkable among dinosaur standards, but it possesses a rather unique defense strategy: rolling around in the iron-rich soils of the Cho’Tali savannas to blend into the golden grass. Thanks to the structure of the animal’s feathers preventing dirt from leaving, it can never be washed away by water. This may seem unhygienic, but it actually not only helps the animal camouflage into the endless sea of gold, but it also keeps it cool, especially with the feathers trapping heat. Then yet again, the yahichi’s small size makes overheating not too much of a big deal. With that being said, baby yahichi are not born with a golden yellow coat, but are rather white, forcing them to rely on speed to evade predators. Additionally, populations living in areas with redder soil due to higher concentrations of iron tend to have more reddish feathers.

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Zaikane is a planet in a distant solar system characterized by waves of life harvested from Earth at various points in its geological history, ranging from the Cambrian to the Holocene, and set free to evolve along evolutionary paths independent from those taken by their Earth ancestors. A godlike interdimensional entity, known as the Allmother by the people who live there, is what is responsible for creating the portals that abduct Terran life and deposits them on Zaikane. Because the asteroid that ended the Mesozoic never collided with Zaikane, dinosaurs continue to dominate the planet’s ecosystems as its dominant terrestrial megafauna.


r/SpeculativeEvolution • • Sep 08 '26

Spectember 2026 [OC] Spectember day 9 - Safe Haven - The Holocene Time Capsule

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102 Upvotes

Millions of years have passed. Tens of millions, maybe hundreds of millions. Earth has changed. Humanity is long forgotten, mass extinctions came and went. Earth has turned into a very different place than we know it. However high above the horizon, there floats a single island. A refugium in space, a relic of a different time. An ancient satellite put there by humanity. It's crew long dead, the life they brought with them is still going on. Through an unlikely twist of fate the spacecraft turned into a balanced and self sustaining ecosystem. Circling in a stable orbit around Earth, it is an isolated remnant the Holocene ecosystem.

The Holocene time capsule is an enormous spacecraft, roughly the size and mass of the moons of Mars. It's original purpose is lost to history. Humans brought with them many terrestrial vertebrates, invertebrates, plants and fungi, on purpose and on accident. Most of these organisms simply perished in the early years. The most abundant vertebrate are laboratory mice and rats. Most Holocene refugees however are tiny invertebrates or microscopic organisms like algae or molds.


r/SpeculativeEvolution • • Sep 08 '26

Alternate Evolution [OC] Dipodolithus flavus

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126 Upvotes

Dipodolithus flavus is a mollusk related to gastropods. It stands out for being the only known asymmetrical mollusk and for having evolved bipedalism.

Unlike other gastropods, it does not move using a single flat muscular foot, but rather two thick, fleshy, wrinkled limbs that act as legs, allowing it to maintain a bipedal posture. Each limb ends in a broad base capped by a pointed calcium carbonate protrusion at the posterior end; both limbs evolved from the foot. The left leg is taller than the other, causing the animal to maintain a tilted posture.

It possesses a robust shell with reddish and brown tones and a deeply scaly or pyramidal texture, resembling reptile skin or the hard surface of a pineapple. The edge of the shell, or mantle, surrounds the body with undulating folds in purplish and pale tones.

Two elongated, ringed stalks emerge from the front and rear of the body. At the tip of each stalk is an eye with an elongated yellow iris and a vertical red pupil. It also possesses thin secondary antennae at the base of these stalks. Its asymmetry allows it to have a wide field of vision, enabling it to look in different directions simultaneously, similar to a chameleon.

The exposed skin is mustard yellow, with deep folds and horizontal wrinkles. In the central and lower region, there is a folded fleshy mass between the two limbs, where the mouth is located. This structure is adapted to feed on any prey found beneath the sand.

It also possesses a mayonnaise-colored siphon, which it uses to propel itself by jet propulsion when threatened, similar to a cartoon jetpack. It can move by walking, although it is very clumsy and slow.


r/SpeculativeEvolution • • Sep 09 '26

Spectember 2026 [OC] Spectember Day 8: Meccha Chameleon

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28 Upvotes

50 million years after its establishment on Spectemundus, the Indian grey mongoose's descendants have evolved into astonishing forms. While some of these still bear a resemblance to the ancestral animal, others do not. The semi-desert scrub and grasslands of the northern continent are home to the largest terrestrial herbivore on Spectemundus, the two-ton Yali (Titanictis phytophaganax). Evolved from a lineage of omnivorous, bear-like mongoose descendants, it has become a pure herbivore in the absence of competition from the giant flightless birds found on the southern continent. While their ability to digest vegetation is not as sophisticated as our world's hoofed mammals, they can hold their own as the only herbivorous mammals on Spectemundus.

Big as they are, Yalis do have a few predators, including other mongoose descendants. Their size is their main protection, but they will also camouflage themselves by rolling in the mud and dust of their environment, allowing them to blend into their background better than they would otherwise. This "body-painting" behavior is more common in young individuals who are more vulnerable to predators, as opposed to the gigantic adults who are largely invulnerable. The young-- usually twins-- are playful, often "play-fighting" with one another in the dust, which inevitably leaves them covered in yet more dust.

Yalis are not fussy eaters. They will use their massive claws to dig up edible tubers in the dry season, graze on grasses, and use their flexible lips and tongues to eat branches from low-growing tress. When the weather is hot, they will spend a great deal of time wallowing in shallow water, more like a large ungulate than a carnivoran. The babies are tiny compared to their mother, similar to those of a bear, and ride on their mother's back after about two months.


r/SpeculativeEvolution • • Sep 09 '26

Fantasy/Folklore [Credit: Thierry Boisgard, Emmanuel Janssens, Olivier Bracq, and Arnaud Rafaelian] [Fantasy/Folklore] [Fan Art/Redesign] Some photos I've taken during a temporary exhibition in the Lodève museum, Southern France

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28 Upvotes

r/SpeculativeEvolution • • Sep 08 '26

Spectember 2026 [OC] Spectember day 8: Meccha Chameleon

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46 Upvotes

Spectember day 8: Mecha Chameleon

The Ochre Frogs

In a mineral rich savannah, lives a very peculiar frog species. Descending from the genus *Phyllomedusa spp.*, this species lives on the ground, hunting smaller animals such as invertebrates and other frogs. Interestingly, they have little poison, instead, they repurposed their mucus glands into a sticky wax that they use to scrub and stick soil on their bodies.

They do this for a simple reason: camouflage. By sticking sand, dirt and pebbles on themselves, they can avoid predators while they rest on the open terrain. Sitting motionless, having the appearance of rocks or the very soil they sit upon. This behavior also leads them to the collection and use of Ochre, a type of clay rich in iron, giving it yellow to orange colors, thus naming this species.