Prehistorica (Christian M.)
@prehistorica.art
Invertebrate Palaeontologist and Palaeoartist from Ontario. Cambrian enthusiast. Worshipper of Omnidens. he/him.
Hallucigenia sparsa, a small lobopodian from the Cambrian-age Burgess Shale, climbing on a sponge.
November 6, 2025 at 5:45 PM
Hallucigenia sparsa, a small lobopodian from the Cambrian-age Burgess Shale, climbing on a sponge.
Papiliomaris kluessendorfae, first reported in 1985 as the Waukesha "Butterfly Animal", was recently described as a strange bivalved arthropod with three pairs of large, feathery appendages. Some reports indicate it could reach up to 20cm wide.
October 8, 2025 at 11:16 PM
Papiliomaris kluessendorfae, first reported in 1985 as the Waukesha "Butterfly Animal", was recently described as a strange bivalved arthropod with three pairs of large, feathery appendages. Some reports indicate it could reach up to 20cm wide.
Multiple lobopodian fossils from the Chengjiang Biota of Cambrian China, including a specimen of two Diania cactiformis, have been found stacked directly on top of each other.
Perhaps a snapshot into the courtship and reproduction of these ancient arthropod ancestors?
Perhaps a snapshot into the courtship and reproduction of these ancient arthropod ancestors?
August 22, 2025 at 5:31 PM
Multiple lobopodian fossils from the Chengjiang Biota of Cambrian China, including a specimen of two Diania cactiformis, have been found stacked directly on top of each other.
Perhaps a snapshot into the courtship and reproduction of these ancient arthropod ancestors?
Perhaps a snapshot into the courtship and reproduction of these ancient arthropod ancestors?
Palaeocampa lived among freshwater fish and sharks like xenacanths, small freshwater arthropods like the bizarre horseshoe crab Alanops, in lakes and rivers among the thriving coal forests of the Carboniferous.
There is no other lobopodian quite like it.
There is no other lobopodian quite like it.
July 23, 2025 at 9:46 AM
Palaeocampa lived among freshwater fish and sharks like xenacanths, small freshwater arthropods like the bizarre horseshoe crab Alanops, in lakes and rivers among the thriving coal forests of the Carboniferous.
There is no other lobopodian quite like it.
There is no other lobopodian quite like it.
In fact, Palaeocampa's spines were not its only defence - the papilale that lined the animals dorsum (the upper surface) are sclerotized, with small pores at their centre which housed small setae.
These armoured papillae gave its back a rough, pebbly appearance.
These armoured papillae gave its back a rough, pebbly appearance.
July 23, 2025 at 9:46 AM
In fact, Palaeocampa's spines were not its only defence - the papilale that lined the animals dorsum (the upper surface) are sclerotized, with small pores at their centre which housed small setae.
These armoured papillae gave its back a rough, pebbly appearance.
These armoured papillae gave its back a rough, pebbly appearance.
It is most similar to Hadranax from the Sirius Passet. They both have stubby, clawless limbs, yet longer than those of velvet worms - they both have elongate frontal appendages, bodies lined with papillae, and a thickened dorsal cuticle.
July 23, 2025 at 9:46 AM
It is most similar to Hadranax from the Sirius Passet. They both have stubby, clawless limbs, yet longer than those of velvet worms - they both have elongate frontal appendages, bodies lined with papillae, and a thickened dorsal cuticle.
Our phylogenetic analysis places Palaeocampa among the Aysheaiids (the classic Burgess Shale animal Aysheaia being its namesake), a group of poorly known lobopodians known from the Cambrian and Ordovician. Palaeocampa is the only known aysheaiid to possess a sclerite armature.
July 23, 2025 at 9:46 AM
Our phylogenetic analysis places Palaeocampa among the Aysheaiids (the classic Burgess Shale animal Aysheaia being its namesake), a group of poorly known lobopodians known from the Cambrian and Ordovician. Palaeocampa is the only known aysheaiid to possess a sclerite armature.
They are septated internally, and serrated externally - even without the poison, these would have been painful to touch. Unlike the urticating hairs of some modern arthropods and plants, these were firmly attached to the body, so their exact function is a mystery.
July 23, 2025 at 9:46 AM
They are septated internally, and serrated externally - even without the poison, these would have been painful to touch. Unlike the urticating hairs of some modern arthropods and plants, these were firmly attached to the body, so their exact function is a mystery.
The spines themselves are incredible, and their preservation is immaculate - these spines are unique in the animal kingdom, even among other lobopodians. They emerge from bundled, modified "basement papillae", and only tape slightly at the top before opening outwards again.
July 23, 2025 at 9:46 AM
The spines themselves are incredible, and their preservation is immaculate - these spines are unique in the animal kingdom, even among other lobopodians. They emerge from bundled, modified "basement papillae", and only tape slightly at the top before opening outwards again.
Our FTIR results support the idea that this fluid, pushed out of the spines upon burial, was likely a natural chemical defence - either poison, or some foul-tasting chemical irritant.
Poisonous lobopodians have been speculated on before, but this is the first solid proof.
Poisonous lobopodians have been speculated on before, but this is the first solid proof.
July 23, 2025 at 9:46 AM
Our FTIR results support the idea that this fluid, pushed out of the spines upon burial, was likely a natural chemical defence - either poison, or some foul-tasting chemical irritant.
Poisonous lobopodians have been speculated on before, but this is the first solid proof.
Poisonous lobopodians have been speculated on before, but this is the first solid proof.
Palaeocampa, unlike its unarmoured aysheaiid relatives, was protected by thousands of tall sclerite bristles, with a thorny, crenellated tip. In many fossils, the sclerites have a discoloured halo of fluid emerging from the tip - we investigated this with a technique called FTIR.
July 23, 2025 at 9:46 AM
Palaeocampa, unlike its unarmoured aysheaiid relatives, was protected by thousands of tall sclerite bristles, with a thorny, crenellated tip. In many fossils, the sclerites have a discoloured halo of fluid emerging from the tip - we investigated this with a technique called FTIR.
This is an entirely new frontier for fossil lobopodians - when did they first enter freshwater environments, and how long did they survive there? How many more are yet to be discovered?
And theres still more.
And theres still more.
July 23, 2025 at 9:46 AM
This is an entirely new frontier for fossil lobopodians - when did they first enter freshwater environments, and how long did they survive there? How many more are yet to be discovered?
And theres still more.
And theres still more.
Until this point, all other lobopodians (except for velvet worms and tardigrades) have been discovered in marine deposits - Palaeocampa's closest relative, Hadranax, lived in the deep sea of the Cambrian.
But Palaeocampa is found up to 300 kilometres inland.
But Palaeocampa is found up to 300 kilometres inland.
July 23, 2025 at 9:46 AM
Until this point, all other lobopodians (except for velvet worms and tardigrades) have been discovered in marine deposits - Palaeocampa's closest relative, Hadranax, lived in the deep sea of the Cambrian.
But Palaeocampa is found up to 300 kilometres inland.
But Palaeocampa is found up to 300 kilometres inland.
Here, we comprehensively redescribe this rare worm from over 40 specimens from both Mazon Creek (USA) and Montceau-les-Mines (France), and deliver the world's first freshwater fossil lobopodian.
July 23, 2025 at 9:46 AM
Here, we comprehensively redescribe this rare worm from over 40 specimens from both Mazon Creek (USA) and Montceau-les-Mines (France), and deliver the world's first freshwater fossil lobopodian.
It has also been considered synonymous with another Mazon Creek worm, Rhaphidiophorus hystrix. We also show that these animals are unrelated, with R. hystrix being an actual fireworm polychaete - with parapodia, true chaetae, and a smooth, segmented cuticle, and a marine habitat.
July 23, 2025 at 9:46 AM
It has also been considered synonymous with another Mazon Creek worm, Rhaphidiophorus hystrix. We also show that these animals are unrelated, with R. hystrix being an actual fireworm polychaete - with parapodia, true chaetae, and a smooth, segmented cuticle, and a marine habitat.
First discovered in Mazon Creek in 1865 by Fielding Meek and Amos Worthen, these fossil worms have baffled scientists for decades.
Their bristly spines resemble modern caterpillars, but later descriptions called it a millipede, a worm, and most recently a fireworm polychaete.
Their bristly spines resemble modern caterpillars, but later descriptions called it a millipede, a worm, and most recently a fireworm polychaete.
July 23, 2025 at 9:46 AM
First discovered in Mazon Creek in 1865 by Fielding Meek and Amos Worthen, these fossil worms have baffled scientists for decades.
Their bristly spines resemble modern caterpillars, but later descriptions called it a millipede, a worm, and most recently a fireworm polychaete.
Their bristly spines resemble modern caterpillars, but later descriptions called it a millipede, a worm, and most recently a fireworm polychaete.
Meet Palaeocampa anthrax, a newly discovered Carboniferous lobopodian, and 150 year old mystery fossil!
Palaeocampa is an exceptional lobopodian - it lived in rivers and lakes, bristled with thousands of poisonous spines, and more. 🧵
Open access: nature.com/articles/s42...
Palaeocampa is an exceptional lobopodian - it lived in rivers and lakes, bristled with thousands of poisonous spines, and more. 🧵
Open access: nature.com/articles/s42...
July 23, 2025 at 9:46 AM
Meet Palaeocampa anthrax, a newly discovered Carboniferous lobopodian, and 150 year old mystery fossil!
Palaeocampa is an exceptional lobopodian - it lived in rivers and lakes, bristled with thousands of poisonous spines, and more. 🧵
Open access: nature.com/articles/s42...
Palaeocampa is an exceptional lobopodian - it lived in rivers and lakes, bristled with thousands of poisonous spines, and more. 🧵
Open access: nature.com/articles/s42...
A swarm of Isotelus maximus gathering to moult and reproduce, stalked in the distance by large nautiloid cephalopods.
June 5, 2025 at 1:08 PM
A swarm of Isotelus maximus gathering to moult and reproduce, stalked in the distance by large nautiloid cephalopods.
Cretoperipatus burmiticus, an equatorial velvet worm from the Cretaceous period.
May 18, 2025 at 8:10 PM
Cretoperipatus burmiticus, an equatorial velvet worm from the Cretaceous period.
Pulmonoscorpius, a 70cm long scorpion from Carboniferous Scotland.
A daytime predator, Pulmonoscorpius was equipped with large compound eyes on the sides of its head, and an enormous stinger. Here, it blends in with the forest, eating a lizard-like Westlothiana.
A daytime predator, Pulmonoscorpius was equipped with large compound eyes on the sides of its head, and an enormous stinger. Here, it blends in with the forest, eating a lizard-like Westlothiana.
May 7, 2025 at 1:14 PM
Pulmonoscorpius, a 70cm long scorpion from Carboniferous Scotland.
A daytime predator, Pulmonoscorpius was equipped with large compound eyes on the sides of its head, and an enormous stinger. Here, it blends in with the forest, eating a lizard-like Westlothiana.
A daytime predator, Pulmonoscorpius was equipped with large compound eyes on the sides of its head, and an enormous stinger. Here, it blends in with the forest, eating a lizard-like Westlothiana.
The mystery 7th tooth is best explained as an unpaired median tooth, dividing the jaws anteriorly - this extra plate was smaller, and more prone to disarticulation. By rectifying this, and examining the remaining diagnostic characters, we find no validity for the new species.
May 6, 2025 at 1:34 PM
The mystery 7th tooth is best explained as an unpaired median tooth, dividing the jaws anteriorly - this extra plate was smaller, and more prone to disarticulation. By rectifying this, and examining the remaining diagnostic characters, we find no validity for the new species.
The problem is: no fossil can be demonstrated to lack the narrowed plates (1 in each half, around the middle) that define O. qiongqii, nor do any fossils have 14 plates - the final “at least 7” is always unpaired, hence the original phrasing.
May 6, 2025 at 1:31 PM
The problem is: no fossil can be demonstrated to lack the narrowed plates (1 in each half, around the middle) that define O. qiongqii, nor do any fossils have 14 plates - the final “at least 7” is always unpaired, hence the original phrasing.
Recently, Li et al. 2024 established that Omnidens had a bipartite mouth, with two opposing “jaws”. They also erected the new species, Omnidens qiongqii. The two key differences were that O. amplus had plates of all equal size, and it had at least 7 plates in each half.
(narrowed tooth circled)
(narrowed tooth circled)
May 6, 2025 at 1:31 PM
Recently, Li et al. 2024 established that Omnidens had a bipartite mouth, with two opposing “jaws”. They also erected the new species, Omnidens qiongqii. The two key differences were that O. amplus had plates of all equal size, and it had at least 7 plates in each half.
(narrowed tooth circled)
(narrowed tooth circled)
New Paper ->
Comment on: Omnidens appendages and the origin of radiodont mouthparts
Are there really 2 species of Omnidens? I comment on the organization of the mouth of this Cambrian apex predator, and argue there is only one species, Omnidens amplus.
onlinelibrary.wiley.com/doi/epdf/10....
Comment on: Omnidens appendages and the origin of radiodont mouthparts
Are there really 2 species of Omnidens? I comment on the organization of the mouth of this Cambrian apex predator, and argue there is only one species, Omnidens amplus.
onlinelibrary.wiley.com/doi/epdf/10....
May 6, 2025 at 1:31 PM
New Paper ->
Comment on: Omnidens appendages and the origin of radiodont mouthparts
Are there really 2 species of Omnidens? I comment on the organization of the mouth of this Cambrian apex predator, and argue there is only one species, Omnidens amplus.
onlinelibrary.wiley.com/doi/epdf/10....
Comment on: Omnidens appendages and the origin of radiodont mouthparts
Are there really 2 species of Omnidens? I comment on the organization of the mouth of this Cambrian apex predator, and argue there is only one species, Omnidens amplus.
onlinelibrary.wiley.com/doi/epdf/10....
Keurbos susanae, a newly described giant arthropod from the Ordovician-age Soom Shale of South Africa.
March 29, 2025 at 11:06 AM
Keurbos susanae, a newly described giant arthropod from the Ordovician-age Soom Shale of South Africa.