By Erin Wayman
Rusty red stains on the head of a fossilized segmented creature found in southwestern China are a paleontological record-breaker: They are the remains of the oldest arthropod brain ever found. The imprint of the 520-million-year-old critter’s three-part brain indicates that complex nervous systems evolved fairly early in animal evolution, among the ancestors of insects, centipedes and crustaceans.
The roughly 7-centimeter-long specimen includes the entire body of Fuxianhuia protensa. The species lived during the Cambrian period, before modern arthropod lineages evolved. The fossil shows F. protensa had a brain composed of three sections that sat in front of the animal’s gut. That’s the same setup seen today in insects, crabs, lobsters and many other arthropods, researchers report in the Oct. 11 Nature.