February 2026 – Nix Illustration

Gomphos

Gomphos elkema was an early lagomorph – closely related to the ancestors of modern rabbits, hares, and pikas – that lived during the Early Eocene, about 56-47 million years ago, in what is now Mongolia and northern China.

Around 20cm long (~8″), it had some anatomical features surprisingly similar to modern rabbits and hares, such as long feet and hindlimbs capable of hopping. But unlike its modern relatives it also had a longer tail, and more “primitive” features in its jaw and teeth that link it to lagomorphs’ shared ancestry with rodents.

Tyrannoroter

Tyrannoroter heberti lived in a lush tropical coal forest covering what is now Nova Scotia, Canada during the late Carboniferous, about 307 million years ago.

It was a member of the pantylid family in the recumbirostran lineage, a group of tetrapods whose evolutionary relationships are still a little uncertain. Traditionally they were classified as lepospondyl “amphibians”, but more recently some studies have found them to be either very early sauropsids or convergently reptile-like stem-amniotes.

Known only from a partial skull and jaw, based on the proportions of its pantylid relatives Tyrannoroter was probably around 30cm long (~1′) and would have resembled a squat lizard with a large blunt triangular head.

It would have had small bony scales within its skin, with interlocking polygonal “armor” on the underside of its jaw and chest, and irregular pebbly scales on other parts of its body. It may also have had claws on its toes, and potentially was capable of burrowing using a combination of its stout limbs and its shovel-like snout.

The roof of its mouth and the inside of its jaw were covered in extensive “batteries” of blunt teeth that show evidence of shearing and grinding motions – suggesting it may have been primarily processing tough plant matter, and making it one of the earliest known herbivorous tetrapods.

Arsinoitherium

Arsinoitherium zitteli was a large herbivorous mammal living in what is now northern Africa during the late Eocene and early Oligocene, about 36-30 million years ago.

Despite looking like a double-horned rhino this resemblance was only superficial, and for most of the 20^th century it was actually the only known representative of an entire order of mammals – the embrithopods – with its wider evolutionary relationships being unknown. Since the 1970s, however, more members of this group have been discovered and embrithopods are now understood to be afrotheres, a very early offshoot of the tethythere lineage, with their closest living relatives being modern elephants and sirenians.

Arsinoitherium was by far the most abundant embrithopod, with numerous fossil remains making it one of the most completely known African fossil mammals. It stood around 1.8m tall at the shoulder (6′), similar in size to modern white rhinos, and would have been a massively-built slow-moving animal with elephant-like columnar limbs.

Its pair of enormous nose horns (and smaller brow horns) were structurally more similar to those of bovids than rhinos, with large hollow bony cores that probably bore thick keratinous sheaths that would have increased their apparent size even more. Both males and females appear to have had these horns, and muscle attachments at the back of the skull suggest Arsinoitherium could powerfully swing its head upwards – possibly wrestling with each other in combat over territories, competing for mates, or in establishing dominance hierarchies.

Manipulonyx

Manipulonyx reshetovi was an alvarezsaurid theropod dinosaur that lived during the Late Cretaceous, about 70 million years ago, in what is now Mongolia.

Although only known from a partial skeleton, based on its close relatives it would have been about 50cm long (~1’8″), with a narrow snout, a coat of fluffy down-like feathers, long slender legs, and short stout arms with massively enlarged thumb claws.

Notably the fossil specimen has the best preserved hands known from the parvicursorine subfamily of alvarezsaurs, revealing a surprising arrangement of three ossified conical spikes around the thumb. These hand spikes were positioned pointing forwards, backwards, and inwards, and may have improved the ability to grip with just one functional finger.

“Spike-like” hand bones were also previously reported in 2009 in another parvicursorine, Ceratonykus, suggesting that these structures weren’t unique to Manipulonyx.

The paper describing Manipulonyx proposes that alvarezsaurs were ovivores, using their hands to carry and then break open eggs, but I’m personally very skeptical of this idea. I think the myrmecophagy interpretation for these little dinosaurs is still much more likely – they probably did opportunistically raid eggs when they could get them, like many modern predators do, but being specialized for just egg-eating is a big claim that definitely needs more evidence.