Oldest Arthropod Brain is Surprisingly Complex

Photo: Xiaoya Ma

My, what large fossilized brain you’ve got! Nicholas Strausfeld of the University
of Arizona and colleagues were studying fossils from China’s Yunnan province
when they encountered a 520-million-year-old brain ever found in an arthropod
(a group of invertebrates that includes insects and crustaceans):

This complex, insectlike brain suggests that rather than insects arising
from simple branchiopods, today’s arthropods descend from a complex-brained
ancestor. Branchiopods would later have shed some of this complexity,
Strausfeld said, while other crustaceans and insects kept it. In fact,
he said, the brain may have evolved to segment into three parts very
early on; mammals, including humans, have a forebrain, midbrain and
hindbrain, suggesting a common organization.

"Lots of people don't like that idea, sharing a brain with a beetle,
but there's good evidence suggesting that you do," Strausfeld said.

Stephanie Pappas of LiveScience has the post: Link