Scientists revealed Wednesday the discovery of a 500-million-year-old larva fossil that still has its brain preserved.
The microscopic creature died during the Cambrian period while still in the earliest stages of its development — the larval stage, according to the study published in the journal Nature. It comes from a new species previously unknown to science, called the Youti yuanshi, which is a combination of two Chinese words that mean “primitive larva.”
The coolest thing about this grain of sand-sized animal is its exceptional level of preservation, allowing scientists to explore never-before-seen details that help explain how arthropods — creatures like insects, spiders, crabs — developed their now-complex brains.
Organ systems of a Cambrian euarthropod larva
Naturehttps://t.co/YffslEtD6R— Ordo Fraterna Fibonacci (@OrdoFibonacci) August 1, 2024
The fossil was uncovered in the Yuanshan rock formation within the Yunnan Province of China and taken to a lab where it was scanned to create a 3D image of the internal structure. (RELATED: Paleontologists Unearth New Dinosaur Species With Unique Skills)
“When I used to daydream about the one fossil I’d most like to discover, I’d always be thinking of an arthropod larva, because developmental data are just so central to understanding their evolution,” said lead author, Durham University paleontologist Martin Smith, according to Live Science. “But larvae are so tiny and fragile, the chances of finding one fossilised are practically zero — or so I thought!”
The scan revealed to Smith and his team a primitive circulatory system showing traces of nerves that supported the creature’s legs and eyes. It’s unclear how the fossil was so well preserved but Smith thinks it had something to do with the level of phosphorus in the waters where it died that helped in the process.