An international team of scientists has discovered exquisitely preserved fossils of the central nervous system from an animal that lived about 520 million years ago. It was one of the oldest and most detailed fossils. Found in southern China, the remains were so well-preserved that you could see the individual nerves. Dr Javier Ortega-Hernandez of the University of Cambridge said it was the first time that this level of detail was observed in a fossil of this age.
The animal was an arthropod
Findings of the study were published in the Proceedings of the National Academy of Sciences. Finding fossilized soft tissues is extremely rare. Most of the fossil remains are bones and other bony parts. The latest findings would help scientists understand how the nervous system of early arthropods evolved. They reveal fine details of the nerve cord in ancient animals.
The preserved animal was an arthropod called Chengjiangocaris kunmingensis. It lived during the Cambrian explosion, when several major groups of animals emerged in a short period of evolution. It belongs to the same phylum arthropoda as animals like crabs, spiders, lobsters, centipedes, and cicadas. The animal looked like a crustacean with a broad, heart-shaped head shield, and a long body.
It is the most complete example of a Cambrian era nervous system
The central nervous system coordinates all motor and neural functions. In arthropods, it consists of a brain and a chain-like series of ganglia that look like a string of beads. Each bead-like ganglia controlled a single pair of walking legs in the animal. Upon careful examination of the ganglia, researchers found dozens of spindly fibers, each measuring five thousandth of a millimeter.
The discovery was made by scientists in the UK, China and Germany. The newly discovered fossils are not the first from the early Cambrian era with preserved parts of a nervous system. But it is undoubtedly the “most complete example of a central nervous system from the Cambrian period,” said Ortega-Hernández.