Complete fossilised nervous system discovered
28 Mar 2016 by Evoluted New Media
A fossil more than 500m years old with a well preserved central nervous system has been found by scientists in southern China.
A fossil more than 500m years old with a well preserved central nervous system has been found by scientists in southern China.
The fossils of Chengjiangocaris kunmingensis have been so well preserved than individual nerves are able to be seen. C. kunmingensis lived during the Cambrian period, 520m years ago. It was an early ancestor of modern arthropods – this phylum includes insects, arachnids and crustaceans.
Dr Javier Ortega-Hernández, study co-author from Cambridge University, said: “This is a unique glimpse into what the ancestral nervous system looked like. It’s the most complete example of a central nervous system from the Cambrian period.”
Researchers have identified partially fossilised nervous systems before, but these have usually been brains, and more often than not the profile of the brain. C. kunmingensis is believed to have resembled a crustacean, with a heart shaped head shield and a long body with legs of varying sizes underneath. Similar to modern arthropods, it had a nerve cord running through its body, with individual ganglia controlling a single pair of walking legs.
Aspects of C. kumingensis’ nervous system have been lost in modern arthropods and tardigrades, but other aspects, namely regularly spaced nerves coming out from the ventral nerve cord, can be seen on priapulids worms and onychophorans (velvet worms).
Dr Xi-guang Zhang, from Yunnan University in China said: “The specimen demonstrates the unique contribution of the fossil record towards understanding the early evolution of animals during the Cambrian period.”
The findings were published in Proceedings of the National Academy of Sciences.
