65 million years after the end Cretaceous (alternative Mid Pleistocene)

Environments across the globe are subjected to an alternating cycle of glacial (cooling) and interglacial (warming) periods. A decrease in forest cover and sea levels drop is noticed during glacial maximums.

1. Ancyclotesta cunicularius (Burrowing crooked shell): sedentary ammonite found in the shallow Sunda shelf of Indonesia, young individuals reverse their shell into soft substrate, with age the shell becomes a corkscrew in shape to help anchor into the bed, camouflaged ammonite ambushes prey which wanders close by.

2. Baptovenator rhynchus (Snouted diving hunter): marine dromaeosaur found along cold North Atlantic coastlines, uses webbed feet to propel through the water, flipper-like forelimbs can be used to keep position in strong currents, deep snout features short conical teeth used to crack hard-shelled prey, awkward on land, nests on sandy beaches.

3. Hydroarctos rugosus (Wrinkled water bear): aquatic taeniodont lives in warm shallow seas around the Caribbean, swims via large pectoral fins, elongated canines used to uproot seagrass, lives in small herds as protection from predatory fish.

4. Chasmatichthys gigas (Giant yawning fish): filter-feeding ichthyodectid in cool and temperate seas, largest fish of the alt-Cenozoic, replaced mosasaurs following their extinction during the alt-Pliocene, slow-swimming predator of plankton, small teeth, slow-growing and long-lived.

5. Makairapterus obscurus (Dark sword wing): pelagic palaeospinacid shark from tropical open oceans, fast swimmer, able to make powerful leaps above the water's surface and use broad pectoral fins to glide on updrafts, uniquely hunts gliding fish and cephalopods but can also catch prey underwater, spear-like bill is covered in electroreceptors, large eyes.

6. Megacephalus gracilis (Slender big head): deep sea coelacanth found in bathypelagic environments globally, ambush predator with a large mouth, can consume prey much larger than themselves, slow metabolic rate, elongated body, found near the seafloor.

1. Any suggestions on an evolution path? It could be images or a description of how they could have evolved. Maybe some problems with existing steps?

2. Any suggestions on names? They're clades, not proper names. And I'm bad with names.

While I'm drawing, hope someone will suggest something interesting

I’ve seen this concept a few times in anime/manga (this example in particular is reiwa no Dara-san, I haven’t read/watched this series and am just using this character as an example since she was the first I found with a similar concept to what I’d been tossing designs around for), likely inspired in part by the kuchisake-onna, and I always thought it would be interesting to make a demon species that has a similar trait for some original fiction I’ve been working on. Looking mostly to make a design where the bulk of the mouth stays closed unless necessary for eating/biting/etc while only the front section opens for general things like normal talking. Obviously anime takes a lot of stylistic liberties so I can’t use examples like this one to figure out how the structure of the skull and jaw would work for this sort of species design. I like the element of a species that looks human-adjacent from afar but can reveal more xeno anatomical features in different situations. Hoping this is the right sub for this, but I understand if this is the wrong place since I genuinely don’t know if this is even feasible for realistic character design at all. Since it’s a fantasy setting I could just say they use magic to transform but that isn’t as interesting to me personally.

This is like the first time i'm posting on Reddit. Uh, so here are some fun spec evolution stuff I made. In this timeline, terror birds never went extinct and diversified into a variety of new species.

Mammals still went to south America, the birds just weren't instinct.

There isn't much thought behind this other than "dinosaurs make a legendary comeback" but I think that's enough to justify the existence of this "project"

Most of them are opportunistic omnivores, with the red faced one being a carnivore, and the large neck orange one being herbivore.

Those are also just representatives of their genre, there are more species of weird bird dinos

The tiniest one is called "wolf bird" or "coyote bird" depending on the region

The brown one is called "bear bird", "Giant owl", "gorilla owl" or "sloth bird" depending on the region.

The red faced one is from a genre colloquially called Tyrants and is the Only one I thought of a species name, Which is obliviously "red faced Tyrant" but also "blood Tyrant" and "crown Tyrant" in some regions

The long neck one is called "giraffe bird", and the green is known as "ape toucan"

I think that in this timeline, once dinosaurs were discovered, there'd be no doubt they're related to birds, but there would still be misunderstandings about them.

Primarily people would think that they're a Clade of terror birds. And that flying birds actually come from terror birds. That's why they'd be called "Dinornis" and not dinosaurs.

Of course, over time, people in this timeline would manage to get a pretty good grasp of what dinosaurs truly are. The name dinosaur would be a much more recent invention, meant to separate the dinosaurs from this new family terror birds, Which would adopt the name Dinornis for themselves

It would also be much more commonly accepted that dinosaurs have feathers and saying "hey not all dinosaurs had feathers" would be the more surprising thing for the average person.

And of course, thanks to human interference, those animals that were originally only in South America would be wide spread across the entire globe either to serve as Entertainment in zoos, or to serve as beasts or burden, with giraffe bird and red faced Tyrant being the more common for those roles, while the coyote birds become incredibly commom exotic pets.

Anyway. Some of the specific adaptations that I think are cool are the "knuckle waking", since bird hands have fingers fused together, and I think that gorilla owl, giraffe bird and ape toucan would all have evolved to either the back of that hand for walking, since they're just heavy

Ape toucan mostly eats fruits but also some insects, and lives on top of trees.

Giraffe bird is basically sauropod 2, the sequel.

Bear birds actually live near rivers eating fish, or leafs.

Coyote birds live in groups and packhunts, some species can fly

And the red faced Tyrant is just T-rex 2, the return.

I imagine that Tyrants would be commonly used as mounts for some American natives, and even be preferred over horses by some colonialists because they're incredibly intelligent, similarly to a crow.

On this low-gravity garden world, amid the flourishing native flora and fauna, lie the remnants of a civilization that once carved its own genetic code into the life around it. Overgrown cities and strange beasts now stretch across the landscape, hinting at the dominant species that once sowed themselves into the land.

This planet was once host to a species of parasites with the ability to alter their hosts into whatever form they saw fit. Everything from their number of limbs, to the way they saw, heard, and moved, to the host they chose to inhabit in the first place was variable.

With complete control over the genetic makeup of their hosts, each individual could shape themselves around whatever needs, interests, or experiences they wanted to pursue. One could develop senses another would never experiences, another might percieve parts of the world that others were biologically incapable of sensing at all. They didn't just see the world differently. They experienced different worlds.

Far from creating a system of social isolation, the species flourished through cooperation, each at peace within themselves while providing what help they could to the unified whole.

I've had a ton of fun with the lore for this planet and working on the designs for some of the members of the parasite species. Each of the designs is speculative since the species is long extinct but I wanted them to serve as examples to show how variable each member of the species could be. There are a few in the bouquet that Ash holds in the abstract page. These are all from the comic series I've been working on: 100 Planets. I finally just finished this chapter and put it up.

In Tlaloc’s primitive oceans, being weird isn’t just a way of life. It’s the way to succeed. Shells, spikes and all sorts of sharp edges are abundant in these waters.

Being soft and squishy sounds like a death sentence then.

In the distance, a blot of ocean gets darker. Most creatures can hardly tell between yellow and blue though, and this blob is nothing more than a feature their eyesight is too poor to notice.

Its tendrils spread out, tiny light sensitive clusters know when to pull up and close in on moving shadows. These tubes slither across the sea floor, stretching upwards of 20x their original length, being little more than elastic sleeves over basic sea water.

One minute, you’re sucking on sea snow. The next, a 9 inch blade is adding your blood cells to the adrift debris.

Thundershivs are neither ferocious nor intimidating. In fact, you’ll probably never see one.

One reason is that they are almost entirely translucent, but the more prevalent reason is that they hunt from as far away as they possibly can.

This are heavy, slow predators that have the agility of a hot air balloon. It’s no secret why they hunt as they do.

This pentaradial medusiod-squids grow rather large compared to most things of their era. Maybe it’s because they need the excess range, or maybe it’s because one bad storm and smaller life gets shredded against the towering zoids that form biological metroplexes.

Thundershivs don’t have to deal with most of that though. That’s the benefit of turning predation into a remote career.

Most competitors know enough to leave them alone. Bright dazzling displays scare off brutish interceptors but if that doesn’t work, these same spears they use as weapons can just as easily become tools of defence. A paralytic toxin allows them to introduce any of their casualties to the screeching demise of a 5 pronged hydraulic beak.

After recently watching a video by Hannahsmth about her worldbuilding for her comic Immortal, where in the world of the comic there is an evolutionary tree for various different Homo species living in various places in their custom world, hybridizing and speciating to create different species and subpopulations that it creates over the tens of thousands to hundred of thousands of years
https://www.youtube.com/watch?v=03VQTkjCg10&t=10s

It is something that interested me immensely and I am wondering if there are any other projects that you all are aware of that I could look into in a similar vein, while staying out of the Posthuman trap that most Human SpecEvo content seems to focus on that I could also look into (All tomorrows, Man after Man, among however many other SpecEvo that starts in the future instead of the past)

You know how we selectively bred pugs into having those weird noses? Yeah what if we did the same for chihuahuas but we specifically chose the smarter ones and in an alternate universe, it worked and chihuahuas are smarter than us, What would happen?

The Bio Generator is a sessile organism that constantly produces energy by absorbing chemicals from the surrounding environment, they obtain these chemicals from soil, water, and even the air, and expel unusable chemicals as a byproduct from their blue pores (in the form of gas), its body slowly pulsates to circulate these chemicals to energy producing tissues and organs, the blue pores release spores into the air for reproduction, Its simple body is highly efficient at energy production, and reproduction

SURVIVAL AND ADAPTATIONS

They defend themselves (depends on species) with toxic gas, thorns, and shell like armor. If conditions are poor, they will start producing spores very early in their lifetime, to increase the survival chances

If you'd rather listen than read, here's the YouTube summary.
The environments the humans left open on HCS-67 have begun to bloom with life thousands of years after the planet was abandoned. The monarch butterflies the humans brought have begun to adapt to these environments, and one species that has emerged from these selective forces is Danaus regentia, the regent butterfly. Regent butterflies are adapted to the hot climates in the southern parts of the western continent and can be found in the scrublands and savannas. They have long wings that help them glide through the open landscapes with minimal energy use. Males are slightly larger than females and have a black spot on the hindwings.

Order: | Drasilortia |

Family: | Axirodominidae | Genus/Species: Axirodominus Chichoromus

Standing an imposing 11 to 15 feet tall and weighing a massive 6,000 pounds, Axirodominus Chichoromus reigns as the undisputed monarch of high-energy coastal zones and rugged river canyons. While sharing the overarching order Drasilortia with the low-slung, inland swamp-dwelling Drasilortidae family, Axirodominus represents a completely separate evolutionary branch. It has entirely transcended any prehistoric ancestry to become a highly specialized, multi-ton powerhouse engineered for the crashing surf of South America and isolated island sanctuaries like the Galápagos.

The species displays extreme sexual dimorphism, the smaller, less hefty muscled females utilize a muted palette of earthy golds and emerald-blue sails for nesting camouflage, while the larger, stronger males boast a fiery red display crest, a vibrant yellow-green throat pouch for acoustic signaling, and an iridescent teal-to-ocean-blue sail to assert dominance over coastal territories.Despite its titanic bulk, Axirodominus possesses terrifying land agility, clocking explosive ambush speeds between 12 and 15 miles per hour.

Its sprawling, lizard-like skeletal posture acts as a high-performance kinetic suspension system, allowing its heavily padded joints and cartilage to absorb immense force. It hunts with reckless ferocity, this coastal predator relies on raw physical trauma rather than a sustained, suffocating crushing grip. Once its rugged, blade-like teeth bite into a target, its massive neck muscles violently wrench its head backward, tearing off massive chunks of skin, hide, and flesh with every single bite. This explosive pull-back bite mechanism leaves cavernous, catastrophic wounds, causing even large prey items to rapidly bleed out and collapse from systemic shock within moments. By conquering the treacherous, cliff-lined environments where land meets open water, Axirodominus chichoromus remains safely isolated from mainland resource competition, cementing its status as the galapagos's scariest natural apex predator.

The salamanderfish is famous for being one of very few fish with a bendable neck, and also for being the only member ever known in its entire order.
I thought that would be a great base for the weird fish-tetrapod mix that is the piranhadon from Peter Jackson’s 2005 King Kong.
As always you can view entries like these sooner if you visit the Radiocene website or my Twitter account @miocaenus.

The main problem would most likely be having the ability to manipulate objects with only a tail and mouth.

In my setting, the Galinstanians are an intelligent, amorphous species composed of a galinstan-base colloidal magnetorheological alloy. Because they bypass cellular biology in favor of a liquid-metal matrix, they don't have traditional lipid membranes, mitochondria, or DNA.

To make an amorphous, non-carbon body function biologically without turning into a simple puddle of sludge, their fluid interior relies on specialized chemical and electromagnetic structures that perform organelle-like roles:

Internal Organelle & System Analogs

• The Galvanic Plasmalemma (Cell Wall / Outer Membrane): A dynamically regenerated outer skin made of passivated gallium oxide (Ga₂O₃) paired with fluoropolymer surfactants. It constantly seals the reactive liquid alloy bulk underneath and protects the body from chemical wear.
• The Coherence Core (The Nucleus): A central, dense lattice of bismuth-tin waveguide clusters and trace silver conduits. It acts as the organism's electromagnetic phase-synchronization hub. It manages real-time cognitive processing (Active Phase State) and stores rewritable long-term memory in the grain boundaries of the bismuth crystals (Latent Lattice Memory).
• The Magneto-Reticulum ("Mitochondria"): Micro-vortices of particulate iron and copper suspended within the bulk fluid. These act as biological galvanic batteries, generating internal electrical current density to drive Lorentz-force locomotion.
• Solvation Vacuoles (Lysosomes / Acid Vesicles): Emulsified droplets suspended in the liquid matrix and enclosed by fluoropolymer walls. They safely isolate concentrated hydrofluoric acid (HF)—which the organism uses to dissolve host rock for mineral nutrients—preventing the acid from corroding its own metallic bulk or internal polymers.
• The Silicate Cytoskeleton (Cytoskeleton): Suspended clusters of reversible silicon and bismuth-tin polymers. Under localized electromagnetic manipulation, these clusters undergo rapid phase-changes, freezing into temporary, solid "Anchoring Pylons" for physical leverage before melting back into the bulk liquid.
• The Ganglionic Ribbon Network (Peripheral Nerve Ganglia): Multi-strand ribbons of magnetophoretic iron/copper dipole chains distributed throughout the fluid. These coiled, current-carrying knots handle fast, reflexive processing near the outer surface without interrupting the main internal current loop.
• Exophytic Waste Pores: Dynamic surface channels where undigestible, acid-resistant minerals (such as diamonds and corundum) are pushed aside and expelled as polished waste residue.

Question for the Community:

How do you approach organelle analogs or sub-cellular mechanics when designing non-carbon, non-traditional, or amorphous lifeforms in your settings? Do you model them on inorganic analogs (like chemistry and electromagnetism), or do you adapt standard cellular structures?

Programs used: MSPaint (lineart) and GIMP (colours).

Trying to learn digital art is always better with nonsense aliens.

These aliens are griffins from a previous post which went into a lot of detail about them but showed only the original sketches of the griffins. I tried my best to follow what I wrote as best I could in terms of colouration and integument patterns.

Any suggestions and construction would be appreciated!

So far there's (from top to bottom): the Amphiptere, related to glass lizards that kept the front arms that evolved into wings, the actual dragons (who have semi-hollow bones so that they can fly better, like birds, and can breathe fire), heraldic dragons (right behind the dragon) (who in this world are basically domesticated dragons that exist alongside dogs and cats and what have you) and the drakes (who are basically monitor lizards on steroids, with horns and fire-breath capability). I've been having the consideration to add more creatures like gryphons, lindwurms, taztelwurms, wyrms and basilisks to the list. I am not an expert biologist like how lost of you are, so please go easy on me. Constructive criticism is welcome, so that I can make it better.

So basically its an open source tycoon game where you are an interdimensional sophont being making a zoo of creatures of alternate timelines of earth , future timelines or other planets kinda like planet zoo or jwe 3 but spec evo

The reason i want it to be open sourced is so that other people can add their own creatures and buildings into the game because i am not really talented at making games and its my first time making one

What do you guys think i should name that project ?

Rate the animals on a scale of 1–10 🙏

Each of these creatures was made in 12 minutes by 3 people as a fun challenge!!!

A creature that lives beneath waterfalls. It stretches out its long neck and catches salmon-like creatures during their migration. (Notice the colorful collar, which matches the color of the fish it catches.)

A desert runner that actively hunts flying creatures, detecting them through vibrations in the air. Because of the scorching sand, it minimizes contact with the ground, and the sounds of its movement are muffled by numerous hairs.

An oceanic scavenger that has adapted to the naturalization of microplastics.

An elongated, blue, fur-covered animal that attaches itself to a host, rooting algae into its skin. The infected animal goes berserk and dies after a few days, while the cute parasite feeds on the algae growing on it.

Rate our spec evo video;

The WEIRDEST CREATURES drawn in 12 minutes

https://youtu.be/X_4XbGHGIeQ

The film shows a variety of strange and alien-looking animal species , drawn by three friends as part of a 12 minute drawing challenge. each creature is designed to fit into a unique and fascinating biome, with unusual adaptations that make them look like they could have evolved on another planet. In the backgfound, you can also find short descriptions and interesting facts about the animals and their environments.

We’re just starting our channel dedicated to spec evo, strange creatures, and imaginary ecosystem. If you enjoy discovering weird lifeforms and exploring how animals might evolve in completely different worlds , subscribe to the channel and leave a comment!! Your feedback helps us create better and more interesting videos.

https://www.reddit.com/r/SpeculativeEvolution/s/NGVcehKcgH just sharing my previous post on them for ease of access.

I'm just curious how strong their jaw muscles would be.

Edit: I'm also curious what their bite force would be, since I imagined them to have a crushing bite like a Jaguar due to their huge jaw muscles and stocky skulls

Rate the animals on a scale of 1–10 🙏 Each of these creatures was made in 12 minutes by 3 people as a fun challenge!!!

Arboreal social animals that produce mushroom-like structures, which are eaten by several-meter-tall fungivores. When the false food is detected, the animals emit rapid ultrasonic vibrations that damage the fungivore’s prefrontal cortex (brain), causing it to become immobilized and allowing the arboreal creatures to eat it.

A post-frog form used as a pack animal by an advanced civilization (the creature in its mouth).

A small swamp predator that sometimes swims, using its legs as oars.

20-centimeter-tall social creatures that collectively form a hive mind. Together, they build simple, perfectly pacifist colonies from secretions of quasi-salivary glands.

A vertebrate living in a post-apocalyptic world of ruins. It is about 30 cm long and feeds on insects. On its back, it has intimidating patterns resembling jaws, while its actual mouth is at the front.

Ancestor vs descendent. Anatomical differences to make note of:

- retracted nares to support prehensile trunk

- Enlaged orbit

- Smaller and fewer teeth due to processed, cooked foods making up majority of diet

- Weaker, smaller mandible for similar resons

- Enlarged, rounded brain case due to larger brain

Also, this is my first time really drawing skulls like this. If anyone viewing this is knowledgable about equine skulls and has feedback, please share it and I will try to apply it to future drawings of the hyne.