Researchers have unearthed fossil of a prehistoric animal from China whose nerves are still visible after more than 500 million years. The crustacean-like animal’s fossilized central nervous system is among the most ancient and detailed system yet discovered, said the researchers.

The fossil is so well preserved that researchers can easily study how nervous system of ancient animals evolved over about 520 million years. The discovery has been published by the Proceedings of the National Academy of Sciences.

Finding ancient remains isn’t rare, but excavating a fossilized soft tissue is extremely infrequent. The new detailed fossil has been discovered in Southern China by researchers from China, Germany and the United Kingdom. The find represents the most detailed example of a well preserved ancient nervous system every unearthed.

The remarkable fossil belongs to Chengjiangocaris kunmingensis, an animal which inhabited earth during the Cambrian explosion. The extinct animal came from a group of animals called fuxianhuiids. Animal experts call it an early ancestor of modern arthropods.

“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”, said Dr Javier Ortega-Hernández, a researcher from the University of Cambridge's Department of Zoology and lead author the research.

In last few years, researchers have found many ancient partially-fossilized nervous systems, but most of them were parts of brains which mean they could only reveal profile of the brain.

Chengjiangocaris kunmingensis looked similar to modern crustacean. It had heart-shaped head shield with pairs of legs. In the latest discovery, the researchers mentioned that they were able to see soft tissues of the 500 million years old animal.