The next time you find yourself calling a clam shrimp a dumbass, you might just be reporting an evolutionary trait instead embarrassing it. Possibly the oldest evidence of a brain ever discovered has been found in Southern China, in the form of a long-extinct fossilized arthropod known as Fuxianhula protensa.
According to Nature magazine , the fossil is over 520 million years old, and is the first example yet of a Fuxianhula specimen with any traces of neuroanatomy still intact. And what impressive neuro-anatomy it was. Though the above picture might make it seem large, the Fuxianhula were only about three inches in length, pre-dating insects and modern malacostracan crustaceans like shrimp and lobsters. The brain, considered far more complex than scientists had previously imagined, is a tripartite, with three segments guiding its sensory input, much like the brains of its modern successors. If the studies prove successful, this fossil may set Fuxianhula as the proverbial missing link within the evolutionary development of insects and crustaceans.
For years, it was believed that insects evolved from a less-complicated branch of the branchiopods, which were themselves thought to have evolved from an even simpler creature, but it’s looking more and more like the Fuxianhula may have been the apex from which an “evolutionary reduction and character reversal” took place, according to neurologist Nicholas Strausfield, an expert in insect neurology.
The human appendix aside, Earthly creatures have a strong tendency to commit to the wayside all forms of superfluous physical properties. The Fuxianhula realized that all it was doing all day was munching on plankton and trying not to die, so it eventually relinquished itself of the ability to consider existentialism, for the greater good. And now that this mystery has become potentially solvable, science now only has roughly 10 billion other unknowns to look into, such as, “What kinds of brains did the things before Fuxianhula have?”