reptile – Nix Illustration

Spectember 2026 #03: Hydra-panosaur

Hydramendax tricephalus is a large Late Triassic drepanosaur, around 1m long (~3’3″). Related to fossorial forms like Skybalonyx, it digs underground burrows using the massive singular claws on its hands — which are specialized to the point of having fully lost all the other digits — and spends its time on the ground rather than climbing around in trees.

No longer used for grip while climbing, its prehensile tail-claw has been repurposed as a “false head“, enlarged and vividly colored to startle and distract predators. A single Mirasaura-like crest plume with similar bold eyespot markings appears to serve as another decoy head, and also as a visual display structure, able to be raised and lowered atop its shoulder hump.

It primarily feeds on insects, using its claws to rip open rotting wood and its long birdlike jaws to probe inside — but it’s somewhat more omnivorous than its relatives and also eats roots and tubers unearthed while burrowing.

Spectember 2026 #01

It’s #Spectember once again, and looking at what’s left of the speculative evolution submissions you all gave me several years ago… I’m actually kind of burnt out on them at this point.

The ones that are left now are a bit too broad, or are just things I currently have no good ideas for — so I’m finally officially calling it quits on that particular batch of prompts. I still won’t be accepting new ideas for the time being; instead this year I’m just going to have some fun with my own concepts.

So! Let’s start off with…

Spectember 2026 #01: Cave Turtle

An illustration of a speculative cave-dwelling softshell turtle. It's pale and fleshy-looking, with no eyes, barbel whiskers on its lower jaw, large paddle-like front flippers, and tiny vestigial hindlimbs.

Voragochelys phantasma is a small turtle descended from present-day softshells, living exclusively in a single deep isolated cave system.

Only around 10cm long (2.5″), it’s completely pigmentless and blind, with tiny vestigial eyes covered by skin. A keen sense of smell and sensitive barbels on its jaw help it navigate in total darkness and locate prey such as smaller crustaceans and fish. It uses large paddle-like forelimbs to swim and haul itself over rocks, while its hindlimbs are highly reduced.

Like its present-day relatives it’s capable of absorbing some oxygen through its thin skin, and also via “pharyngeal breathing” — the inside of its mouth and throat are lined with numerous fleshy projections that massively increase the surface area and act like gills, allowing for gas exchange when water is pumped in and out. Its incredibly low metabolic rate means it can remain fully submerged almost indefinitely, sometimes barely moving for years at a time.

Females lay small clutches of eggs once every decade or so in rock crevices just out of the water, and similarly to the present-day pig-nosed turtle their hatching is triggered by seasonal flooding.

Simosaurus

Simosaurus gaillardoti was a marine reptile that lived in shallow tropical seas covering much of what is now Europe and the Middle East, about 242-235 million years ago.

It was part of the nothosaurian lineage, a group of semi-aquatic sauropterygians that were widespread throughout the Triassic seas before the rise of the more fully marine plesiosaurs.

Growing up to around 4m long (~13′), Simosaurus had a flat short-snouted skull and rather thick blunted teeth, along with jaw musculature adapted for a quick strong snapping bite — suggesting it specialized in crushing tough prey like shelled cephalopods and hard-scaled fish.

Lentamanusuchus

Lentamanusuchus hubeiensis was a small marine reptile that lived during the early Triassic, about 248 million years ago, in shallow tropical seas covering what is now southwestern China.

It was part of a group known as hupehsuchians, early cousins of ichthyosaurs that had toothless jaws, paddle-shaped limbs, eel-like tails, and distinctive bony armor along their backs.

Around 1.2m long (~4′), Lentamanusuchus had particularly broad flippers with extra bones in its hands, a transitional state between its ancestors and later polydactylous hupehsuchians.

Galahadosuchus

Galahadosuchus jonesi was a small early crocodylomorph that lived during the late Triassic of what is now southwest England, around 215 million years ago.

About 60cm long (~2′), it had a fully upright quadrupedal posture, slender digitigrade limbs, a long tail, and a paired row of interlocking osteoderms running along its back.

Its habitat at the time was part of an archipelago of small tropical islands, in a forested karst environment full of sinkholes and caves. It would have been a fast and agile runner, and like its close relative Terrestrisuchus it was probably a generalist pursuit predator feeding on prey such as invertebrates and smaller reptiles.

Saniwa

Saniwa ensidens was a varanid lizard that lived during the Eocene, about 49 million years ago, in what is now Wyoming, USA.

Closely related to monitor lizards, it would have grown to about 2m long (~6’6″) and looked very similar to modern forms, with a pointed snout, well-developed limbs, and a proportionally long tail.

But it also had something not seen in any other jawed vertebrate — a total of four eyes.

Many lizards have a single prominent parietal “third eye” on the top of their heads, which are light-sensitive and involved with both regulating circadian rhythms and hormone production for thermoregulation. However, Saniwa ensidens had two of these structures, with one formed from the parapineal gland like in other lizards, and the second positioned behind it formed by the pineal gland. The only other vertebrates with this arrangement are the jawless lampreys, suggesting that Saniwa somehow re-evolved a pineal eye hundreds of millions of years after its distant ancestors had lost it.

It’s not clear what this extra eye was used for. It would have increased the pineal complex’s sensitivity to blue-wavelength light, and may have been involved in orientation and navigation using polarized light similar to some modern lizards — or possibly magnetoreception-based navigation similar to some modern newts.

Solnhofia

Solnhofia parsonsi was a turtle that lived in the tropical seas covering what is now Europe during the Late Jurassic, about 150-148 million years ago.

Around 20cm long (~8″), it had a long pointed beak and a large triangular head that would have supported powerful jaw muscles, which it may have used to crush hard-shelled invertebrate prey.

Its relatively short limbs are more similar to those of freshwater turtles than the long flippers of oceanic-swimming sea turtles, suggesting Solnhofia was adapted to shallow coastal waters and lagoons rather than the open sea.

Some specimens have considerably shorter tails than others, which may represent the same sort of sexual dimorphism as seen in modern sea turtles – with the longer-tailed individuals being males, and the shorter-tailed ones females.

One fossil’s carapace also shows predation tooth marks from a marine crocodilian similar to Dakosaurus.

Austriadactylus

Austriadactylus cristatus was an early pterosaur that lived during the Late Triassic, about 215 million years ago, in what is now Austria and Italy.

It’s one of the most basal (“primitive”) pterosaurs currently known, with its long tail lacking the stiffening bony rods seen in other early “rhamphorhynchoid-grade” forms.

It had a wingspan of around 1.2m (~2′), and a bony crest on its snout that grew taller towards the front. Its jaws contained a mix of two different tooth types – a few long pointed teeth and numerous smaller three-pointed teeth – with wear patterns that suggest its diet primarily consisted of hard-shelled invertebrates.

Xiphodracon

Xiphodracon goldencapensis was an ichthyosaur that lived in marine waters covering what is now the Jurassic Coast of the southern United Kingdom during the Early Jurassic, about 188 million years ago.

Around 3m long (~10′), it had fairly large eyes and a long narrow snout lined with small slender pointed teeth.

It was part of the leptonectid family, closely related to other long-snouted forms like Eurhinosaurus. Although currently only represented by a single fossil specimen, it’s actually the most complete ichthyosaur known from the Pliensbachian age of the Early Jurassic.

Preserved gut contents show that it primarily fed on fish, and also that its stomach was positioned on the left side of its body. The fossilized individual also suffered from multiple injuries during its life, including malformed teeth, a fractured clavicle, and avascular necrosis in its upper limb bones. It appears to have died after a bite to the skull from a predator – likely the larger ichthyosaur Temnodontosaurus – and additional bite marks on one hindlimb may be evidence of scavenger activity.

Spectember/Spectober 2025 #06: A Curiously Charged Choristodere

The Dark Master requested: “Maybe a speculative Placodont or choristoderes. Feel free to do anything, just if they had continued to evolve and survive”

A digital sketch of a speculative descendant of choristodere reptiles. It's an aquatic lizard-like animal with a wide flat head with long narrow jaws, a long neck, four webbed paddle-like limbs, and a long eel-like tail.

In a slightly different timeline to our own, the last surviving choristodere Lazarussuchus didn’t go extinct during the Miocene. Instead it survived in European waterways until the Messinian salinity crisis, and dispersed down into northern Africa when the Strait of Gibraltar closed up.

During one of the “Green Sahara” humid periods its descendants made their way further south, and now Keravnodraco dominusobscuri is found in lakes and rivers throughout the rainforests of West and Central Africa.

About 1m long (3’3″), it hunts small fish and aquatic invertebrates in dark murky waters, using a unique set of electrogenic organs in its elongated neck to actively sense the bioelectric fields of prey in dark murky waters – and also generating electric shocks that can stun its targets or deter predators.