Edaphosaurids were a fairly early branch of the synapsids – the evolutionary lineage whose only surviving members are modern mammals – and were some of the earliest known tetrapods to develop into large specialized herbivores. They also had huge spiny sails on their backs resembling those seen in their cousins the sphenacodontids (including the famous Dimetrodon), but the two groups actually evolved those features completely independently of each other.

Although their fossils are known from both North America and Europe, their European remains are very rare and fragmentary. Currently the best-known specimen is made up of a recently-discovered partial spinal column and a few hand and tail bones.

Given the name Remigiomontanus robustus, this edaphosaurid lived in western Germany during the end of the Carboniferous and the start of the Permian, around 300-298 million years ago. About 1.2m long (3’11”), it seems to represent an intermediate form between small insectivorous-or-omnivorous edaphosaurids like Ianthasaurus and the huge herbivorous Edaphosaurus.

(Interestingly the paper that names Remigiomontanus also makes a brief mention that the protruding cross-bars on edaphosaurid sails may have anchored larger keratinous coverings, which could have made them look even more spectacularly spiky and suggests their sails may have served an anti-predator function. Hopefully if this is true we’ll see further information get officially published about it sometime!)


Fossils of pterosaurs are already rather rare due to their fragile hollow bones — and they’re especially scarce in Australia, with only a handful of fragments known.

But recently a more complete one was discovered in central-western Queensland.

Ferrodraco lentoni (“Lenton‘s iron dragon”) is named after the ironstone that the fossils were found in, and while it’s known only from a partial skull, some pieces of its neck and wings, and various teeth, it’s still by far the best pterosaur specimen ever found in Australia.

Living during the mid-Cretaceous, somewhere between 94 and 90 million years ago, it had a 4m wingspan (~13′) and was also one of the very last of its kind. It was a member of the ornithocheirids, a group characterized by rounded crests at the tips of their long toothy jaws, which were previously thought to have all gone extinct by that time.

Many of Australia’s Cretaceous animals were close relatives of those found in South America, due to an earlier land connection via Antarctica, but surprisingly Ferrodraco wasn’t particularly closely related to any South American ornithocheirids. Instead it seems to have been part of a lineage known from halfway around the world in Europe, suggesting that these pterosaurs were capable of crossing long distances over oceans to disperse between continents.

Eons Roundup 4

Some more recent commission work for PBS Eons!

The entelodonts Eoentelodon and Brachyhyops, from “The Hellacious Lives of the Hell Pigs”

The early ichthyosaur Tholodus and the mosasaurPluridens, from “When Ichthyosaurs Led a Revolution in the Seas”

The early bats Onychonycteris and Icaronycteris, from “When Bats Took Flight”


Originating from Japanese monster movies like Godzilla, the word “kaiju” is now often used to refer to giant creatures in general – and so it was only a matter of time before a huge sauropod dinosaur was named after the concept.

Kaijutitan maui* was a titanosaur living in Argentina during the Late Cretaceous, about 89-86 million years ago. It’s only known from fragmentary remains, so its full size is difficult to estimate, but it was probably somewhere in the region of 20m long (66′). Nowhere close to the largest sauropod, but possibly one of the heaviest since it does seem to have been rather chunkily built, with stout limbs and an estimated weight of 40-60 tonnes (44-66 US tons).

* Not named for the Polynesian hero, apparently, but for the initials of the Museo Argentino Urquiza.


The modern sperm whale is already an impressive animal, being by far the largest of the living toothed whales and famous for its ability to dive over 2km down (1.2 miles) to feed on deep-sea animals like giant squid.

But some of its ancient relatives were terrifying.

Livyatan melvillei here has an appropriately monstrous name, inspired by both the Hebrew name for the Leviathan and Herman Melville, the author of Moby-Dick. Known from the Pacific coast of South America during the late Miocene, around 10-9 million years ago, it’s estimated to have measured somewhere between 13.5m and 17.5m long (~44′-57′) – comparable in size to an adult male sperm whale.

Unlike the relatively slender mouth of its modern cousin, however, it instead had thick strong jaws full of enormous teeth.

Livyatan melvillei skull by Ghedoghedo | CC BY-SA 4.0
(for an idea of the sheer size of this reconstructed skull – some of those teeth are almost the length of your forearm)

It was part of a loose grouping of what are known as “macroraptorial sperm whales“, which all had similarly toothy jaws and occupied the same sort of ecological niche as modern orcas, specializing in hunting prey like large fish, squid, seals, and other whales.

Livyatan‘s main food source was probably smaller baleen whales about half its own size, and its only real competition for this prey was the equally huge megalodon shark that shared the same waters.

A huge fossil tooth found in Australia suggests that Livyatan or a very close relative of it survived at least into the early Pliocene, about 5 million years ago. Around this time a cooling climate and dwindling numbers of its preferred prey would have eventually made a population of such enormous apex predators unsustainable, and driven this “killer sperm whale” into extinction – probably around the same time megalodon disappeared, about 3.6 million years ago.

Hello there!

Welcome to the long-overdue new version of Nix Illustration!

Please pardon our dust – we’re working on getting everything properly set up here, and also importing in around six years’ worth of archived content from elsewhere.

In the meantime, you can find more complete selections of work at any of these places:
Tumblr | Pillowfort | Twitter | Patreon

Current status as of 23/10/19:
all 2019 content uploaded
–2018 in progress


Bothremydids were an extinct group of side-necked turtles that existed from the late Cretaceous to the early Miocene, between about 100 and 20 million years ago. Found across most of the world (with the exception of Antarctica and Australia) they were a diverse group occupying a range of ecological niches, inhabiting both freshwater and near-shore marine habitats.

Although their fossils are mainly just fragmentary remains like pieces of shell, Chupacabrachelys complexus here is actually known from a fairly complete skeleton.

Living in what is now western Texas, USA, during the late Cretaceous (~75 mya), it was an average-sized member of the group at around 1m long (3’3″) and was probably marine, swimming around in the shallow tropical waters of the Western Interior Seaway.

It had a particularly unusual skull for a turtle, narrow and triangular and slightly flattened, with elongated eye sockets. The paleontologists who described Chupacabrachelys thought the overall shape was vaguely reminiscent of a canid, and so that ended up inspiring its name — a reference to the mangy coyotes that are occasionally mistaken for the mythical chupacabra.

Sollasina cthulhu

Ophiocistioids were a group of weird and poorly-understood echinoderms which lived between the early Ordovician and the late Triassic, about 475 to 233 million years ago. Related to modern sea cucumbers, they were squat dome-shaped creatures with clusters of tentacle-like scaly tube feet, and have been compared to the bizarre fictional monsters of H. P. Lovecraft’s Cthulhu Mythos.

So it’s not really surprising that one of them has been named Sollasina cthulhu.

But unlike its namesake this “monster” was actually tiny, only 3cm across (1.2″). It was discovered in the fine-grained Wenlock limestones of the UK, and dates to the late Silurian, about 430 million years ago. Its exceptionally well-preserved state makes it the first ophiocistioid with known fossilized internal structures, including evidence of its water vascular system.

Unfortunately this high level of detail comes at a cost — the tiny Wenlock fossils are preserved in three dimensions inside hard concretions and are almost impossible to extract or interpret from split-open cross-sections, and highly expensive CT scans don’t give a good enough resolution. So the only way to actually “see” them is to destroy them, grinding away a tiny layer at a time and taking a photograph at each step, then assembling a digital reconstruction from the hundreds of slices.

Island Weirdness #61 — Tiny Elephants On Parade Part 6: Eastern Mediterranean

Alongside the weird deer, otters, and owls, the island of Crete also had dwarf elephants — and much like Sardinia to the west the Cretan elephants were actually descendants of mammoths rather than the Palaeoloxodon seen in the rest of the Mediterranean.

A stylized illustration of an extinct pygmy mammoth. It has gently curving tusks, small ears, and a body shape more like a baby elephant.
Mammuthus creticus

Mammuthus creticus was originally thought to also be a palaeoloxodontine, but more recent studies of its anatomy and ancient DNA have confirmed it was indeed another tiny mammoth. It was probably descended from either the Southern mammoth or Mammuthus rumanus, which would have arrived on Crete during the late Pliocene or early Pleistocene between about 3.5 and 1 million years ago.

Isolated on Crete, with no predators and living at a time when the island was much smaller, it quickly dwarfed and became the tiniest known mammoth to ever exist, standing just 1.1m tall at the shoulder (3’7″). Not much is known about its ecology, but its teeth suggest it was a browser feeding on leaves and shrubs, possibly filling a similar niche to the mid-sized deer that came later.

This mini-mammoth seems to have gone extinct by the mid-Pleistocene, about 1 million years ago, around the time when rising sea levels during an interglacial phase may have submerged so much of the smaller proto-Crete that its population could no longer be supported.

Later in the mid-to-late Pleistocene, after the sea level dropped again and tectonic uplift brought Crete close to its modern dimensions, the small mammoths were replaced by both newly-arriving deer and Palaeoloxodon elephants, which evolved into the much more moderately dwarfed forms of Palaeoloxodon creutzburgi and Palaeoloxodon chaniensis.

A stylized illustration of an extinct dwarf elephant. It has long thin tusks and small ears.
Palaeoloxodon tiliensis

To the north and east of Crete the Cyclades and Dodecanese islands had endemic dwarf elephants on at least eight islands, with the best known being the species that lived on Tilos.

Palaeoloxodon tiliensis stood about 1.8m tall (5’11”), on the larger side for a dwarf Mediterranean elephant but still one of the smallest palaeoloxodontines in the Aegean region. Several thousand specimens have been found, and radiocarbon dating shows it was a fairly recent evolutionary development, appearing just 45,000 years ago in the late Pleistocene.

This dwarf elephant was also the very latest surviving of its entire kind, living well into the Holocene until at least 4000 BCE. This is several thousand years after humans first arrived on Tilos, suggesting it was a rare case of an island elephant that managed to endure the effects of a human presence for quite some time.

In fact there’s some speculation that Palaeoloxodon tiliensis (or a similar unknown species) may have survived for even longer than that, since one Ancient Egyptian tomb from around 1480-1400 BCE contains a painting depicting traders with exotic animals, including what appears to be a small hairy elephant with slender limbs and thin upward-curving tusks. We may never know for certain if this was actually a late-surviving dwarf, a mutant modern elephant, or just artistic license with scaling, but the possibility is still intriguing.

A stylized illustration of an extinct dwarf elephant. It has long gently curving tusks and small ears.
Palaeoloxodon cypriotes

Over on isolated Cyprus further to the east, the only native large mammals were the miniature hippos and an equally miniature elephant.

Palaeoloxodon cypriotes was smaller than the Aegean palaeoloxodontines, about 1.4m tall (4’7″), and much like its cousin on Tilos seems to have evolved very recently towards the end of the Pleistocene, sometime around 20,000 years ago.

It wasn’t the first dwarf elephant on Cyprus — there was a larger, earlier species known as Palaeoloxodon xylophagou at least 200,000 years ago — but it’s not clear whether these two species represent a single evolutionary line or two entirely different colonizations of the island.

Similarly to the hippos it lived alongside, Palaeoloxodon cypriotes disappeared shortly after humans arrived on Cyprus, between 12,000 and 10,000 years ago. Collections of its bones have been found in a rock shelter with evidence of having been burnt, suggesting that it was being actively hunted and cooked.

And that’s all for the Island Weirdness series! Even over two months there are still plenty of species I didn’t have time to feature, so this definitely won’t be the last we see of strange endemic species.

Thank you for following along — with a shoutout to my Patreon supporters! — and regular weekly art posts will resume here next Monday.

Island Weirdness #60 — Hippopotamus minor

Cyprus is one of the most isolated islands in the Mediterranean, having had no close connections to the mainland for the last 5.3 million years and being uplifted to close to its modern size during the Pleistocene. As a result it had very few land mammals, all of which arrived by swimming or rafting: rodents, shrews, a genet, dwarf elephants, and a dwarf hippopotamus.

Hippopotamus minor (sometimes called Phanourios minor) seems to have been descended from the common hippo, which probably swam across to Cyprus from the Levant region sometime in the mid-to-late Pleistocene, around 400,000 years ago. Isolated with no predators and limited space it rapidly became dwarfed compared to its ancestors, reaching at most 75cm tall at the shoulder (2’6″) — making it the tiniest known island hippo, and slightly smaller than the modern pygmy hippo.

It became much more terrestrial, with more digitgrade feet adapted for walking and climbing over rugged rocky terrain. Its teeth suggest a diet of pig-like browsing on forest vegetation — and much like pigs (and other hippos) they may have been opportunistic omnivores occasionally also eating small animals and carrion.

Despite being so small for a hippo, it was still one of the largest animals living on Cyprus, weighing about the same as the dwarf elephants it lived alongside. It also seems to have been the most common of the mammals on the island, with remains of thousands of individuals having been found.

While larger dwarf hippos are known from several other Mediterranean islands, the Cypriot species is the only one that seems to have survived into the early Holocene.

The earliest known evidence of humans in Cyprus comes from a rock shelter on the southern coast, dating to about 12,000 years ago, consisting of stone tools and a massive concentration of burned animal bones — with over 200,000 of them coming just from Hippopotamus minor. It’s possible that in addition to being so abundant on the island, the dwarf hippos’ evolution in the absence of predators meant they had no fear of humans and were much less aggressive than their larger relatives, making them particularly easy to hunt and kill.

…Or they were just especially tasty.

Later deposits from about 2000 years later show no sign of the hippos at all, with their role in the Cypriot ecosystem completely replaced by introduced species like deer, sheep, and goats.