Scientists Scan 300 Million Year Old Brain

Researchers using holotomography to create 3D images of fossilized fish have found a 300 million year old intact brain in a specimen from Kansas. This is the oldest known example of any type of brain and should providing some interesting new insights into brain evolution and function. The visual lobe and optic nerve look similar to modern brains but the area that regulates orientation and balance doesn't connect to three ear canal loops. Instead, the orientation sense is a flat plane, so the fish could sense side to side movements but not up and down. Also unusual, the brain is much smaller than the brain case. Could it be brain shrinkage after the animal's death? Alan Pradel, one of the researchers, says there is no sign of brain deformation that would result from shrinkage and some very old existing fish species such as coelacanths have a similar arrangement. Ironically, a Walmart store now covers the location where the Kansas fossil originated from but scientists plan to scan similar fossils found in Oklahoma and Texas. For more details see the 3D video of the brain scan after the break or the press release from ESRF, where the brain was scanned, or the recent Neurophilosophy or Neurobiotaxis blog posts. For all the technical details, see the paper on the find, Skull and brain of a 300-million-year-old chimaeroid fish revealed by synchrotron holotomography