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A 319-million-year-old fossilized fish pulled from a coal mine in England more than a century ago has revealed the oldest example of a well-preserved vertebrate brain, researchers say.
Scans show the creature’s skull contains a brain and nerves in the back of the brain that are approximately 1 inch (2.5 cm) long.
The scientists from the University of Birmingham and the University of Michigan (USA) believe that the discovery opens a window on the structure of the brain and nervous system and the early evolution of a large group of fish living today – ray-finned fish.
The findings shed new light on the preservation of soft tissue in fossils of spined animals, the researchers suggest.
Most animal fossils in museum collections are formed from hard body parts such as bones, teeth, and shells.
Senior Author Dr. Sam Giles of the University of Birmingham said: “This unexpected discovery of a three-dimensional vertebrate brain gives us an amazing insight into the neural anatomy of ray-finned fish.
“It shows us a more complicated pattern of brain development than is suggested from living species alone, and allows us to better define how and when modern-day bony fish evolved.”
“Comparisons with living fish showed that the brains of Coccocephalus most closely resemble the brains of sturgeon and paddlefish, which are often referred to as ‘primitive’ fish because they differed from all other living ray-finned fish more than 300 million years ago.”
Researchers analyzed the brain of a Coccocephalus wildian early ray-finned fish about the size of a bream that swam in an estuary and likely fed on small crustaceans, aquatic insects, and cephalopods, a group that now includes squid, cuttlefish, and cuttlefish.
Ray-finned fish have backbones and fins supported by bony rods called rays.
While soft tissues such as the brain usually decay quickly and very rarely fossilize, when this fish died, the fossilization process replaced the brain with a dense mineral that preserved the three-dimensional structure of the soft tissue.
Lead author Rodrigo Figueroa, also from the University of Michigan, commented: “This superficially inconspicuous and small fossil not only shows us the oldest example of a fossilized vertebrate brain, but it also shows so much of what we know about the evolution of the brain through that.” Life thought species alone need to be revised.”
This unexpected discovery of a three-dimensional vertebrate brain gives us a startling look at the neural anatomy of ray-finned fish
dr Sam Giles, University of Birmingham
University of Michigan senior author Matt Friedman said: “A key takeaway is that these types of soft tissues can be preserved, and they can be preserved in fossils that we’ve had for a long time — this is a fossil that’s been around for over.” Known for 100 years.”
The research is published in Nature.
The fossil from England is the only known specimen of its kind, so scientists could only use techniques that did not destroy it.
The skull fossil is on loan to the University of Michigan from the Manchester Museum.
It was recovered from the roof of the Mountain Fourfoot coal mine in Lancashire and first scientifically described in 1925.
scientists believe C. wildi would have been six to eight inches long, and based on the shape of its jaws, it was likely a carnivore.
When the fish died, it was likely quickly buried in low-oxygen sediments — an environment that can slow the decomposition of soft body parts.
