#spectember

[theantiazdarcho]

The Lancetfish is a species that looks like it comes straight out of a realistic fantasy world building project.

[alphynix]

Spectember 2025 #02: A Little Shell-Fish

Another anonymous request asked for a "terrestrial placoderm":

Keluphichthys pezoporus is a descendant of Bothriolepis-like Devonian placoderms. Inhabiting shallow freshwater environments, they often used their rigid jointed fins to scramble short distances over land to reach new isolated ephemeral pools, and they developed convergently lung-like structures that could exchange gases directly from air, allowing them to survive in poorly-oxygenated waters and make even longer terrestrial journeys.

While the end-Devonian extinction devastated all other placoderms, this odd lineage survived into the Carboniferous, eventually raising themselves up to walk fully on their two limbs using a heavily scaled tail for balance.

Due to the relative weight of its bony carapace Keluphichthys is a fairly small animal, standing about 10cm tall (~4"). Its high domed body shape allows it to right itself when overturned, and resists the bite forces of larger predators such as the early tetrapods it lives alongside.

Its jaws are protrusible, with bony blades fused into a serrated "beak" used to snatch up invertebrate prey.

It's still reliant on wet environments, needing to stay moist and returning to pools of water in order to reproduce. Juveniles start out aquatic and gradually transition to terrestrial habits as they mature.

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[tribbetherium]

SPECTEMBER 2025: WHAT IF? (PART 3)

What if... (HUGE ORIGINAL SKETCHES SPOILERS AHEAD)

...the omegaham was an extremely-derived daggoth?

The Late Terminocene, 500+ million years P.E.

The final epoch of HP-02017 has come to its end. Long ago, it was a lush and thriving world, but now it is no longer.

Only the most extreme of lifeforms have survived the end of days, as the climate grew more and more uninhabitable. The planet was now in an irreversible spiral of desertification, and soon, as its oceans grew ever smaller and saltier, and as forests and grasslands gave way to arid desert, the survivors would be only the most bizarre creatures ever to walk the planet.

One lineage, the saharats, would soldier on. Descended from daggoths, whose anatomy was so peculiar they were scarcely recognizable as rodents, or even vertebrates, their ability to endure the heat, need little food and water, and bear hundreds of microscopic, quasi-larval young that could remain dormant in dessication-proof sacs and halt their development until conditions became favorable, allowed them to survive the apocalyptic environment. They, at this point, are the last surviving clade of hamsters.

But one very unusual group began taking on a remarkable evolutionary route. To reduce its surface area exposed to the blistering heat, it would develop a dense coat of heat-reflecting hair that protected its skin both from intense sun and the chill of night. Its nasal tendrils would greatly reduce to small lobes that covered its nostrils and mouth to reduce the loss of moisture, and its limbs would become smaller, with four appendages in particular becoming larger and the primary organs of propulsion. For traction these would develop lateral fleshy pads that, over time, would develop keratinous pseudo-claws to enable it to grasp food and grip the ground in conjunction with the main true claw as it foraged. A pair of large, hairless flanges on its head acted as heat sinks to help it regulate its temperature, and, due to its crepuscular habits, its rows of numerous ocelli would eventually fuse into two large light-sensitive aggregate structures, which could be covered over by flaps of skin to keep out damage and irritation by particles of sand or excess light.

This successful design would end up outliving the rest of the daggoths, after a period of sudden extremes followed by a brief respite of the heat would cause a mass extinction of the remaining species, but allow the one lucky survivor to briefly flourish.

And, over half a billion years later, the only species left was...a hamster.

It looked almost identical to one, and was genetically one. Yet, had one been able to observe it inside, everything within was uncannily wrong. Its skull was mishappen by flanges and fenestrae that supported the muscles of its facial tendrils. Its eyes were devoid of sockets, but instead bore a series of miniscule pits from the nerve cords of its numerous now-fused ocelli. Its limbs were fingers, attached to the wrists and ankles of limbs now but all gone. Even on the outside, this species was unlike its bygone kin in strange ways. Its numerous ocelli flaps, closing in unison, made its eyes close and open in a disconcerting zipper-like fasion. Its fleshy "nose" and "lips" could peel apart in three fused lobes to reveal its true nose and mouth. And it reproduced by producing great numbers of dessication-resistant pods containing tiny undeveloped young less that a few millimeters long, more akin to a fish or crustacean spawning roe than anything resembling live birth.

500+ million years in the future, at the end of it all, one species holds on defiantly, for as long as it can in the face of the final extinction. A creature that, on the surface looks almost identical to the primordial progenitor of all this planet's fauna from beginning to end: but also one so intrinsically and incomprehensibly different, a hidden testament to its evolutionary ancestry spanning unfathomable stretches of deep time.

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[makairodonx]

A bonus creature feature made just to end of Spectember 2024! A mother Western Whale-Mole and her calf rise up to the surface of the cold ocean waters surrounding the southern coast of Svarogia to take in a breath of fresh air. Swarming around the giant marine mammals are flocks of two different seabird species that are both endemic to Svarogia: white, ternlike like relatives of hummingbirds and orange-headed, gannet-like relatives of starlings. At 14 to 18 meters long and weighing up to 42 metric tons, the Western Whale-Mole or Aquacondylura orientalis is one of the most common species of the Whale-Moles, a family of giant, aquatic moles that may have evolved from fossorial, pig or cow-sized ancestors millions of years earlier, and it thrives across the seas lying within the planet's Southern Temperate Zone. Western Whale-Moles usually migrate north to the tropics for the lagoons of island chains such as the Strzelecki Archipelago in which they can calve, and the families will soon head further south where shoals of feeder fish or krill have been brought up by the cold, nutrient-righ waters of Potworia's great southern ocean. Like all whale-moles, the Western Whale-Mole usually uses its long, whisker-lined rostrum and clawed flippers, the latter of which are also sometimes used for fighting, to dig up the ocean floor in order to forage for tuna-sized fish and crustaceans, and it is capable of smelling underwater by exhaling large air-bubbles onto any objects or scent-trails and inhaling the bubbles to carry scents back to its nostrills. These same bubbles are also used by individuals gathering together to trap fish or krill in a bubble-net feeding strategy similar to the one used by Earth's humback whales.

[kek-evo]

For 2020's "Spectember", I came up with the "shrøøp" - a future elephant shrew descendant that's taken a page from the book of platybelodon (who's often nicknamed "scøøp" or "scööp" in paleo memes) and become something of a shovel-tusker.

The purpose of this particular evolutionary speculation is not so much to consider how the elephant shrew might adapt to future selection pressures but rather to demonstrate how absolutely ridiculous platybelodon's "trunk" looks no matter what animal is sporting it. Look at that thing. smh

[nazrigar]

Beast Fables - Megafauna of the Continents Part 1.

So since this IS spectember, I've been doing a lot of explorations of what kind of megafauna in my worldbuilding project of Beast Fables. Urvara is basically kinda of like an "Earth but more" place. The continents are roughly in similar places, but there's a LOT more wildlife to go around, from ground sloths to toxodons (here called rhippo) to sebecids and even a singular Eurypterid.

North Ambrosia helps establish the "range" of potential Megafauna, including some of the biggest of the big in the setting, while South Ambrosia shows what happens when you get REALLY biodiverse.

[mezoa]

new spec project i've been working on: Aquadonts!

set in an alternate Middle Jurassic where marine reptiles never dominated, mammal-like synapsids descended from forms such as the real life Castorocauda fill the seas. Here we have Castorocauda, a real-life extinct mammaliform synapsid with a beaver-like tail:

its descendents, the Pelagocaudids (informally Aquadonts) diversify into whale and sauropterygian-like niches with a few primitive twists

with primitive lips, and fish-beaver like tails being ancestral to the family, i'm having a lot of fun designing the transitionary forms. i'm unsure if it's actually certain whether castorocauda's paddle was horizontal like whales or vertical like fish, so for an interesting and possibly? speculative element i've opted to design them with vertical paddles and retaining long frontal limbs to grapple and grasp

Unlike modern mammals, these crown mammal-related synapsids haven't been through an evolutionary bottleneck of nocturnality, meaning the pelagocaudid family are capable of seeing and producing a wide array of traditionally non-mammalian colours blues, vibrant indigos and rich sandy oranges manifest as elaborate patterns on these creatures. They also still retain the genetic and evolutionary toolkit to tap into somewhat reptilian atavistic traits, and without muscular lips to rely on in a turbulent coastal lifestyle, evolutionary pressure has selected for tough, keratinised snouts. stay tuned for more!

[eternal-gromnommer]

A very late Spectember entry, but I was inspired by @alphynix 's "Dicyny World" where archosaurs and cynodonts never got to take over and the planet was instead dominated by the descendants of the dicynodont Lystrosaurus (which was famous for dominating in the aftermath of the Great Dying that ended the Permian).

So here's a bunch of random species, playing around with the idea of dicynodonts having superficial or convergent features of mammals, squamates and birds to fill niches similar to all of those, as well as the idea that drab coloration and color-blindness in mammals were a side effect of their nocturnal Mesozoic ancestry so other synapsids could probably be quite colorful.

Clockwise from top:

• The Tookey, an arboreal species adapted for climbing, similar to primates, squirrels and the arboreal synapsid Suminia, that feeds on leaves, seeds and insects in the treetops, using prehensile paws and a balancing tail to navigate among the branches.

• The Tuskbird, part of a pterosaur-like flying clade. This species is mostly ground-dwelling, however, similar to galliform birds, with males sporting brightly-colored iron-rich tusks for display. They eat primarily seeds, which they crack open with their short, blunt bills, as well as other plant matter.

• The Goliphant, a megafaunal herbivore that grazes on low-lying vegetation such as ferns and shrubs and grass-equivalents. Older bulls sport bright colors on their faces to display to conspecifics. Populations at different latitudes have differing amounts of body hair, being furrier in colder regions.

* The Puffrus, a semi-aquatic omnivore that spends most of its life at sea, feeding on marine plants and shellfish, but returns to land to breed as it is oviparous like most other non-therian therapsids, forming colonies on the shore where they guard their eggs in densely-clustered nests until hatching.

* The Spearbill, a plains-dwelling omnivore with a long beak that can be used to probe into burrows for small animals, break into insect nests like an anteater and pick up seeds and fruit-analogues. Its comb-like tusks are used for grooming, and its long limbs make it an adept runner.

* The Leazle, a small carnivore analogous to something between a mustelid and a monitor lizard, with a long body and short limbs ideal for chasing small prey down their burrows, both in the ground and up in tree trunks. A hooked beak and fang-like tusks help hold on to struggling prey.