Posted on 10/26/2025 10:55:24 PM PDT by Red Badger
This ancient fossil holds the oldest intact brain ever discovered, and it looks strikingly like that of a spider,
© Credit: Nicholas Strausfeld Share this post A fossil found in southern China has revealed something scientists rarely get to see: the incredibly well-preserved brain and nervous system of a 520-million-year-old creature. It belonged to a now-extinct marine animal with big front claws and a body that shares surprising similarities with today’s spiders and scorpions.
The fossil, part of the Alalcomenaeus genus, offers a detailed snapshot of early arthropod evolution. Researchers discovered that its nervous system, especially the brain and nerve cords, was still visible, giving them a rare chance to study how such animals may have functioned. Thanks to modern scanning techniques, the find has helped confirm a link between these ancient creatures and modern arachnids.
A Brain Built Like a Spider’s Found in the Chengjiang fossil site in South China, this animal was part of the megacheirans, a group of marine arthropods known for their large claws. Their bodies were segmented and equipped with multiple limbs for crawling or swimming.
What really got scientists’ attention was the fossil’s brain. It showed clear structures that match up with the central nervous systems of animals like horseshoe crabs and scorpions. Dr. Greg Edgecombe from London’s Natural History Museum said this points to a close evolutionary connection between megacheirans and modern spiders. He explained in an interview with BBC News that:
“The nervous system is one of the more reliable tool-kits we have. We were trying to investigate whether there was evidence for the preservation of neural tissues from very early parts of the animal fossil record.”
The discovery helps the team to place megacheirans closer to arachnids on the evolutionary tree, showing that their ancestors likely lived alongside early crustaceans.
The fossilized nervous system of Alalcomenaeus. Credit: N.Strausfeld/University of Arizona
Peering Inside With 3D Tech
To uncover these hidden features, researchers used CT scanning and digital 3D software. That let them look beneath the surface of the fossil without damaging it.
“People like myself who are mad keen on creepy crawlies want to understand how very strange early arthropods relate to living ones,” remarked Dr. Edgecombe.
What they found was a concentrated mass of neural tissue in the head and segments of the brain that were directly connected to the animal’s large claws. Xiaoya Ma, also from the Natural History Museum, said the clarity of the structures gave scientists a rare opportunity to compare the brain of this ancient animal with those of modern arthropods. According to Ma, it’s the most complete nervous system ever seen in a fossil from this time period.
University of Arizona professor Nicholas Strausfeld, who worked on the anatomy side of the study, said the brain layout looked surprisingly familiar. He pointed out that the position of the claws supports the idea that spiders’ biting mouthparts evolved from these same appendages.
The head’s structure clearly marks where the two front claws would have projected. Credit: N.Strausfeld/University of Arizona
What A 520-million-year-old Brain Says About Spiders
Usually, scientists use exoskeletons and external features to place fossils in the evolutionary timeline. But in this case, the nervous system gave them a clearer picture. That kind of internal anatomy makes it easier to link ancient species to animals alive today.
Strausfeld explained that these early creatures likely lived in the same environments as the ancestors of crustaceans, back in the Lower Cambrian seas. According to him, the preserved nervous system makes a strong case that spiders and their relatives branched off from a shared ancestor much earlier than some had thought. The discovery, published in Nature, opens the door to finding more ancient fossils with preserved neural tissue.
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PinGGG!.......................
Spider Spider on the wall...
What is the last thing that goes through an insect’s mind when it hits a car?
It’s behind.
Origin of Species no longer has explanatory power.
Species-to-species evolution, so-called “macroevolution”, or Darwinian evolution, as opposed to intra-species minor variation, has been discredited. Debunked.
The author of this article apparently can’t contend with this reality.
A sea creature with similarities with today’s spiders and scorpions.
In other words, a crab or lobster — insects of the sea.
Sleepy Joe Biden asks if he could please have it.
Regards,
Spider sweetbreads, anyone?
What is the best scientific explanation now?
They scanned the fossil using X-rays...they didn’t look at the brain with eyeballs. the neural tissue is closer to horseshoe crabs and scorpions...which supposedly (thinking like an evolutionist)makes them closer to spiders.
Title says brain looks like a spiders. That is outright hyperbole. Science writer should be barred from ever contributing. May have been AI assisted garbage.
"Sweetbreads" is the culinary term for the thymus gland - which is located in the chest cavity of all vertebrates.
No invertebrates possess a thymus gland.
Regards,
Climate Change? Dark Matter? Whatever can’t be proven.
Ris d’veau? Now you’re making me hungry! 🤤
Spiderman! Spiderman!
Does whatever a spider can!
Spins a web, any size!
Catches thieves just like flies!
Look out!
Here comes the Spider-Man!.........................
Thanks to the world wide web, we learn of this much faster than ever before.
Well that explains the black widows.
You mean Jill asked. If only Sleepy Joe was aware he needed a brain.
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