In a groundbreaking discovery, a 455-million-year-old fossil fish has provided valuable insights into the evolution of brain protection mechanisms in vertebrates. The findings, detailed in a paper published in the journal Nature Today on Wednesday, September 20th, were the result of collaborative research conducted by scientists from the University of Birmingham, the Naturalis Biodiversity Centre in Leiden, Netherlands, and the Natural History Museum.
The research, generously funded by the Leverhulme Trust, focused on the fossilized remains of Eriptychius americanus, an ancient jawless fish discovered in ancient deposits located in Colorado, USA. What sets this fossil apart is its uniquely preserved skull, which differs significantly from any previously documented specimens. This discovery has filled a 100-million-year gap in the evolutionary history of vertebrate skulls.
Using advanced computed tomography, a sophisticated x-ray technique, scientists were able to create a highly detailed 3D representation of Eriptychius’s skull. This groundbreaking reconstruction marks the first time such a comprehensive analysis has been conducted on this specimen, which was originally collected in the 1940s, described in the 1960s, and is now housed in the Field Museum of Natural History in Chicago.
What sets Eriptychius apart is the presence of separated, independent cartilages that encase the brain, in contrast to the solid bone or cartilage structures found in later jawless and jawed fish species. While subsequent species developed a fully enclosed cartilage cage to protect the brain, this discovery suggests that the early stages of brain protection mechanisms may have begun with Eriptychius.
Dr. Ivan Sansom, Senior Lecturer in Palaeobiology at the University of Birmingham and senior author of the study, expressed his excitement about these findings, emphasizing their potential to unveil the early evolutionary history of how primitive vertebrates safeguarded their brains. He also underscored the importance of museum collections and the application of cutting-edge techniques in paleontological research.
Dr. Richard Dearden, Postdoctoral Research Fellow in Palaeobiology at the Naturalis Biodiversity Center and lead author of the paper, highlighted the significance of this discovery, despite Eriptychius not being the most visually striking fossil. He noted that modern imaging techniques revealed the unique preservation of the oldest three-dimensionally preserved vertebrate head in the fossil record, addressing a substantial gap in our understanding of skull evolution across all vertebrates, including humans.
Source: Nature Today
