r/SpecEvoFandom

A random Komodo Dragon evolving into a Spinosaurus, such a dangerous combination

(Some context and anatomical notes)

This species would be the equivalent to earth’s Pandericthys, not necessarily the first “fish” to crawl on land but one of the predecessors. It is a bottom dwelling species in shallow brackish ecosystems, feeding on small organisms in the mud.

The front limbs are similar to those of lobe finned fish, with the fin tip made from three bone fingers and a handful of rays between each. A ring of plates line the oral cavity, with two pairs of mandibular limbs surrounding it. The tail fin is actually adapted from a third limb, derived from a structure superficially similar to the tripod fish. The dorsal and anal fin are supported by structures eventually adapted into the hip. The spine of these animals are located near the bottom of the animal, gradually raising and ending in the dorsal fin, with the body cavity sitting in a canoe shaped rib cage.

Most of the things said I said about the anatomy here would also apply to other “fish” in this world. Let me know what you think!

The creature depicted is a scientifically grounded reinterpretation of one of Twixxel's Stalkers from the Minecraft mod. It is presented as a large specialized primate that could have evolved under realistic biological pressures in a high oxygen prehistoric environment.

The iconic white face with black eyes is retained as a form of disruptive coloration and mimicry. In many primates contrasting facial patterns serve for communication intimidation and signaling. Here the pale face could reduce the threat silhouette at a distance by mimicking a smaller less dangerous primate or hominin. The oversized dark eyes provide excellent low light vision. This creates the signature uncanny floating head effect when the creature stalks in darkness exactly as seen in the original concept.

The long limbed dark body is interpreted as a massive quadrupedal primate standing about four meters tall at the shoulder. Thick bones and heavy musculature address the square cube law allowing it to support several tons of weight without collapsing. It primarily moves on all fours for speed and endurance during long stalks but can rear upright to display dominance or intimidate rivals and predators. This matches the tall imposing posture in the original images while remaining structurally sound for a large terrestrial animal.

The matte black fur and skin provide near perfect blending in shadows caves and dense forests. Sickle shaped claws and a powerful jaw equipped with strong teeth enable brutal kills and processing of varied prey. The overall build supports an omnivorous opportunistic apex predator lifestyle with high intelligence and patience.

This version could have arisen in a high oxygen prehistoric setting which would have supported larger body sizes denser muscle tissue and higher sustained activity levels. It represents a specialized hominoid lineage that prioritized stealth patience and raw physical power. It would have evolved alongside but avoided direct competition with early humans or other hominins.

What happens when a population of massive macropredatory turtles are released into one of America's most famous swamps?

First photo from the creator of Kappa on YouTube

Second photo... I don't know

Nothing to explain

The Arachne are an indigenous race of arachnid sophonts to the planet of Vulcanis which has high gravity and a high geothermal activity. Though, it does have large quantities of plant life and water (kept from boiling due to higher atmospheric pressures). It is very unpredictable and dangerous, which makes the Arachne all the more miraculous.

1. How are they giant spiders?

True insects or something similar never properly evolved on Vulcanis. Though it has a high oxygen atmosphere, the high gravity makes exoskeletons impractical, so the clade of Dermoarthropoda evolved instead, (colloquially: "skinsects".) ((Or skin-rachnids, in this case, I suppose.))

Point of the matter is: the "insects" on Vulcanis have a more vertebrate-like structures with endoskeletons and such. The larger ones have more vertebrate-like nervous/circulatory/respiratory/etc systems as well, cuz those don't scale all too well the bigger the animal.

1.2 Why do they appear to have an exoskeleton then?

They do not. What they have is a hardened layer of skin they use as protection for their rocky and hot homeplanet. The "hardened cuticle" as it's primarily called is akin more in structure to the scales of a pangolin than it is a bone or an exoskeleton.

2. How do they not get crushed then?

Despite their looks and relatively large size, they are not all that heavy. The bulk of their body's weight is their "skin-shell", and their bones, naturally. Even so, their weight is well-distributed amongst their six walking limbs (again, pretend I drew six instead of four.).

2.1 How do they have the brainpower for all those limbs? Vertebrates on Earth can only have a maximum of 4 limbs, after all.

Vulcanis' primary ancestor for most animals had eight limbs (mostly for movement) so many of the creatures on the planet have either 8 fully functional limbs, multiple dominant limbs and several vestigial ones, or the brainpower to manage eight limbs.

3. Why are they smart?

Vulcanis is a very unpredictable planet with unsure odds of finding food or ensuring your offspring survive. That tends to breed three things:

A. Big dumb things that are tough enough to withstand whatever is thrown at them long enough to eat and make a bunch of babies.

B. Many dumb small things that are numerous enough to eat and make a bunch of babies.

C. Medium-to-small smart things that can outwit the odds and make a few babies.

The Arachne's ancestors evolved towards the third. It also tends to breed aggressive things which make the species that do protect their young very good at doing so.

Inherent protective parental behavior towards their young in the face of high predation gave the Arachne's a kickstart to evolving towards sentience. In addition, Arachne aren't exactly the toughest critters around relative to other Vulcanites, so intellect and the ability to yeet rocks real good served as a decent substitute.

4. Why spiders of all creatures as an evolutionary background?

One of the primary ones is that spiders are very well-designed creatures. On such a usually uneven and unpredictable surface, having lots of limbs is good for manuervability. In addition, they're quite stable physically, which is really good in general. Though they can't crawl on walls (cuz Square-Cube law) they can do the next best thing and climb with those distinctive clawed gecko-like digits, which is made much easier by their 6-limbed origins. Their four eyes are good for watching out for predators, too.

Though they lack the hydraulic movement of the spiders of Earth for ensnaring prey, they have something just as suitable: body slamming. In short, they'll set up a lure, (their silk used to be for web-making, but as you can imagine: giant spiders can't hide in webs without breaking em', but they are good for making nests in general.) climb somewhere high up and when their prey sniff-sniffs... SNAP. They drop down with their chelicerae out and bite down HARD or just straight-up crush their prey beneath their bodies, assuming a flattened "spider-pancake" pose. Though they can crouch or flex as needed.

The shock is absorbed through their many limbs, which spreads the sudden force out better.

Because this hunting method is so effective, they just... never evolved anything better and continue to be the bodyslamming bugs I know and love.

(OC)

What if a population of Haast's Eagles (Hieraaetus moorei) were released into Yellowstone National Park?

Can the American Lion Survive the Serinaustran Steppes of the Early Ultimocene in the World for Serina?

Photos belong to their respective owners.

I first saw the trailer and I thought this was gonna be buns and then I forgot about it for like 3 years. Now that I finally watched it. THIS WAS ABSOLUTELY AWSOME. I gotta put some respect on it, that pilot was peak. Sure there was some pacing bits thst were a bit strange but I think this has the most potential in the dinosaur fantasy stuff compared to the new Prehisoria sex slop made my Vivin.

ALSO MOMMY LIGHTING SPINO