The find puzzles scientists

Mar 3, 2009 08:43 GMT  ·  By
A 3D model of the 300 million-year-old fish, which still preserves its brain
   A 3D model of the 300 million-year-old fish, which still preserves its brain

Since the beginning of archeology and anthropology, scientists working in these fields have been looking for the oldest brain on the planet, whichever its origins may be. It would appear that now their prayers have been answered, as a 300 million-year-old fossil, recently found in Kansas, revealed the contents of its skull – a very well-preserved brain that can potentially answer a lot of questions about how more intelligent animals came to be, and how their neural pathways developed from this early ancestor.

“Soft tissue has fossilized in the past, but it is usually muscle and organs like kidneys because of phosphate bacteria from the gut that permeates into tissue and preserves its features. Fossilized brains are unusual, and this is by far the oldest known example,” New York City American Museum of Natural History paleontologist, John Maisey, explained. He said that the fish's brain structure resembled that of modern ratfishes, most commonly known as “ghost sharks” or chimaeras.

“There is nothing like this known today; it is really bizarre. But now that we know that brains might be preserved in such ancient fossils, we can start looking for others. We are limited in information about early vertebrate brains, and the evolution of the brain lies at the core of vertebrate history,” he added. The new fossil had a huge skull, large eye sockets, and fierce teeth, which were placed in the mouth on many rows. Its brain kept one optic nerve, which showed its connection to the appropriate area of the brain.

Paris Museum of Natural History paleontologist Alan Pradel explained that “For a long time, paleontologists have used the shape of the cranial cavity to research the general morphology of the brain – because soft tissue was not available until today.” Now, with the help of CAT scans and an X-ray synchrotron, researchers can create sophisticated 3D models of ancient fish brains, which will provide them with extensive knowledge on how they came to develop over the years.