There’s an article in Nature (479, 270 (17 November 2011) on that Cambrian crustacean with the rather unusual eyes: “Ancient creature’s surprising sight”:
The fossilized compound eyes of a crustacean that lived around half a billion years ago reveal a surprisingly sophisticated visual system that was probably able to detect motion and gauge distance in many directions.
Resembling a tiny mace, the eye consists of four distinct areas atop a stalk measuring at most 0.5 millimetres in length. The four overlapping zones scanned mainly forwards, backwards, to the outer sides and inner sides, respectively.
Probably served the same purpose as movable scanning lights.
See also: Cambrian explosion: See Darwinist. See hat. See Darwinist wave hands. See rabbit
Multi-stage life cycles date back to the Cambrian?