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