How fossilization preserved a 310-million-year-old horseshoe crab’s brain
A newly analyzed specimen is a ‘one-in-a-million’ find, researchers say
The brain (white at center) of an extinct horseshoe crab called Euproops danae was fossilized in a clay mineral called kaolinite. The whole crab stretches only about 10 millimeters.
R. Bicknell