Thursday, October 24, 2013

A Nervous System Half a Billion Years Old

An amazing fossil was unearthed in China last year. It is the imprint of a common marine organism, Alalcomenaeus, but even though it is 500 million years old its preservation is so astonishing that scientists were able to extract a map of its nervous system. Fossil on the left; two different scans in the center, and then the two scans overlapped; on the right, map of the nerves.

This drawing, from Not Exactly Rocket Science, compares the nervous system of Alalcomenaeus (pop) with that of a larval horseshoe crab; you can see that the basic plan of the arthropod nervous system had been established by 500 million years ago. Actually arthropods have two different nervous system plans, and we know now that both plans existed by 500 million years ago.

It astonishes me that we can know such things about animals that lived in such a remote world.

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