Nix Illustration – Page 5 – Paleontology and science illustration

Luoxiongichthys

Luoxiongichthys hyperdorsalis was an early ginglymodian ray-finned fish, related to the ancestors of modern gars, living during the Middle Triassic (~244 million years ago) in coastal tropical marine waters covering what is now southwestern China.

About 15cm long (~6″), it had a large hump on its back shaped like a backwards shark fin. Its deep body was wider at the base, giving it a triangular shape when viewed from the front similar to some modern tropical fish – and suggesting it may have had a similar sort of ecology as a slow but highly maneuverable swimmer feeding on small seabed invertebrates.

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.

Megabalaena

Megabalaena sapporoensis was a member of the balaenid baleen whale lineage, related to modern right whales and bowhead whales. Living in marine waters covering what is now northern Japan during the late Miocene, about 9 million years ago, it helps to fill in a significant gap in the fossil record of this group.

Known from a partial skeleton about 12.7m long (~42′), it was much larger than earlier balaenids, but smaller than modern forms. It also had a narrower flipper shape compared to its modern relatives, a less arched jaw, and its neck vertebrae were only partially fused.

Modern right whales are slow-swimming ram feeders, but since Megabalaena was less specialized for this particular filter feeding style it’s unclear what its ecology was.

Dimacrodon

Dimacrodon hottoni was a synapsid that lived during the mid-Permian, about 272 million years ago, in what is now Texas, USA.

Known only from incomplete skull material, it had a thin bony crest on its forehead and a long snout with unusually toothless jaw tips — which had a rough bone texture suggesting there was a small keratinous beak there.

Its full body proportions aren’t known, but since its skull measured around 50cm (~1’8″) it was probably at least 2.5-3m long (~8-10′).

When its fossil remains were first discovered in the mid-20^th century it was thought to be a dicynodont-like anomodont, but later examination in the 1990s suggested it was actually a more basal “pelycosaur-grade” synapsid, possibly a sphenacodont close to early therapsids. There hasn’t been any further study on Dimacrodon since then, though, so its exact evolutionary relationships remain very murky.

Its ecology is equally unclear, but its beak-like jaws suggest it may have been somewhat herbivorous. It would have lived around a coastal river delta in a semi-arid climate, alongside herbivorous caseids like Cotylorhynchus and Angelosaurus, predatory sphenacodontids like Dimetrodon, small lizard-like parareptiles and captorhinids, and aquatic temnospondyl amphibians.

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 #08: Alphabugs

One last entry for this year!

Dwoll suggested “a family of creatures that have evolved to look like every letter of the Roman/English alphabet”:

A digital sketch of a speculative treehopper bug. It has a large elaborate "helmet" crest on the back of its neck forming a shape that resembles the letter A.

Grafficimex dwolli is a domesticated species of treehopper closely related to the neotropical genus Cladonota.

Its wild ancestor, the now-extinct species Grafficimex ignotus, had an elaborate pronotum “helmet” with a close resemblance to the English letter F. It proved to be surprisingly easy to raise in captivity, being docile around humans and happily using common houseplants such as Monstera as hosts, and it was also quite morphologically variable. Varieties resembling letters such as E, C, and U were quickly developed, and hobbyists began competing to breed more and more new shapes.

Now, after centuries of selective breeding, the English alphabet has been completed, along with a couple of recently-developed breeds with bulbous protrusions that resemble question mark and exclamation mark shapes.

An "alphabet" of speculative Grafficimex treehoppers with crests that resemble the letters from A to Z, along with a pair that resemble a question mark and an exclamation mark.

(Breeds resembling the alphabets of other languages are also in development.)

At about 2cm long (~0.8″), Grafficimex dwolli is rather large for a treehopper, and much like the domestic silk moth it has almost entirely lost the ability to fly.

Along with being kept as novelty pets, often carefully lined up on plant stems to spell out amusing messages, these insects are also quite popular with beekeepers – the honeydew produced by Grafficimex nymphs and adults can be harvested by bees to make dark strong-flavored honeydew honey.

Spectember/Spectober 2025 #07: Kelp Yourself

An anonymous submission asked for a “live bearing bird”:

A digital sketch of a speculative aquatic descendant of moa birds, shown swimming in a kelp forest. It has a small head with a turtle-like beak, a long neck, no wings at all, a streamlined body, and large flipper-like webbed feet. Clumps of long ribbon-like feathers run down its back, vaguely mimicking the appearing of kelp fronds.

Rimurimuornis ovovivipara is a future descendant of the broad-billed moa, in a timeline where these Aotearoan birds weren’t hunted to extinction.

About 2m long (~6’6″), this fully aquatic bird grazes in kelp forests and seagrass meadows. It’s a rather slow swimmer, propelled solely by its large flipper-like feet – because like all moa it completely lacks wings.

Its ancestors’ laid incredibly thin-shelled eggs, and a combination of reducing the hard shell away even further to a more leathery state, then increasing egg retention time inside females’ bodies, has led to this lineage evolving an ovoviviparous form of live birth at sea.

It also has long ribbon-like feathers along its back that mimic the appearance of seaweed fronds. While terrestrial moa have few large predators to worry about, Rimurimuornis has to contend with sharks, orca-like whales, and leopard seal-like pinnipeds, and if its camouflage fails its primary tactic to discourage attacks is defensive defecation.

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.

Spectember/Spectober 2025 #05: Strangels

We’re continuing into Spectober with another anonymous request, this one asking for: “Hominids that evolved with 6 limbs, 2 of which are wings. Limb placement is up to you.”

A digital sketch of a speculative six-limbed hominind, pictured in both tree-climbing and gliding poses. It has a monkey-like face with very large eyes, opposable thumbs and first toes, no tail, short fur over its body – and an extra pair of "arms" hanging just behind its shoulders that end in stubby fingerless hands and support a large gliding membrane. In the aerial pose it's shown grabbing hold of its wing-limbs to hold them in place for gliding.

Living several million years in a possible future, Anomalangelus anthropogenis is a bizarre case of a six-limbed primate.

Its additional pair of upper limbs originate from a heritable form of notomelic polymelia, similar to the Developmental Duplications condition seen in our time’s domestic cattle. It has a rather chimeric genome that appears to contain ancestry from several different hominid lineages, suggesting that this strange little creature actually descends from something that was originally genetically engineered.

It’s a tiny dwarfed species, only about 25cm long (~10″), with a highly arboreal omnivorous loris-like lifestyle, spending most of its life clambering around in trees. Although its extra limbs can’t move independently, lacking a lot of functional musculature and nerve connections, they’ve been exapted into brightly-patterned display structures and also serve as attachment for a large gliding membrane – Anomalangelus uses its forelimbs to grab hold of these “wings” while airborne, spreading them out and stabilizing them to form a composite wing.

Spectember 2025 #04: Kerguelen Kingdom

A couple of anonymous submissions asked for “Kerguelen fauna before it sank 20 million years ago” and “a predator which prowled Cenozoic Kerguelen before it sank”:

[Context: The Kerguelen Plateau is today almost entirely underwater, but during the Cretaceous Period much larger parts were above water as island landmasses. Initially forming during the Gondwanan breakup of what would become Australia, India, and Antarctica, it was eventually left isolated in the forming southern Indian Ocean, and due to long-term volcanic hotspot activity it may have gone through as many as three different periods of rising and sinking before finally almost completely submerging about 20 million years ago.]

In the early Cenozoic, around the time of the Paleocene-Eocene Thermal Maximum, there’s less of Kerguelen’s land above water than there was in the Cretaceous, but the climate is warm-temperate and conifer forests cover the plateau’s islands.

A digital sketch of a speculative descendant of enantiornitheans. It's a large chunky shaggy-feathered flightless bird with a small head, toothed jaws instead of a beak, a long neck, vestigial wings with small claws, thick legs, and a pair of ribbon-like tail feathers that end in wider spaded plumes.

Enantiochen reliquia is a flightless bird standing around 1.5m tall (~5′), and its toothy jaws, wing claws, and ornamental ribbon-like tail plumes on males identify this species as an enantiornithean, descended from a small flighted form that just barely survived through the K-Pg extinction here.

It’s the largest current inhabitant of the Kerguelen plateau, a browsing herbivore filling a similar ecological role to the later moa of Aotearoa.

A digital sketch of a speculative descendant of gondwanatherian mammals. It vaguely resembles a rabbit with small pointed ears, with a deep snout, long digging claws on its digits, a short thin tail, and long hind feet.

Cuniculitherium kerguelensis is another Mesozoic holdover, a gondwanatherian mammal — although a little less unique than Enantiochen since other gondwanatheres still also survive in early Cenozoic South America and Antarctica.

About 40cm long (~1’4″), it’s a rather rabbit-like burrowing herbivore with long hind feet and a fast bounding gait, traits its lineage originally evolved to evade unenlagiine theropods and small terrestrial crocodylomorphs prior to the end-Cretaceous extinction. Those predators are gone from Kerguelen now, but…

A digital sketch of a speculative descendant of australobatrachian frogs. It has a large head, short chunky limbs, and an elongated body with a row of bony amor plates along its spine.

Daptobatrachus archaeotropus is a descendant of australobatrachian frogs. In a case of island gigantism it’s close to the size of a cat, around 50cm long (~1’8″), and with its elongated body, stubby hind legs, and a row of osteoderms down its back, it almost looks like a throwback to the Permian.

Although unable to hop, it’s an ambush predator capable of raising itself up for very brief bursts of crocodile-like galloping, preying on pretty much anything it can potentially fit into its mouth.