Shark-sized Cambrian predator had compound eyes

Nature : Anomalocaris was a shark-sized, soft-bodied predator that inhabited the oceans in the Cambrian period. Possessing two front claw-like limbs, it looked like a shrimp, but with fins instead of legs. New fossil evidence has revealed another resemblance to shrimps and other arthropods: Anomalocaris had compound eyes. What’s more, each of the two eyes of Anomalocaris contained at least 16 000 individual hexagonal lenses. Although modern dragonflies have 28 000 lenses per eye, ants and files have far fewer and likely cannot see as clearly as Anomalocaris could. The lens-containing fossils were discovered in a shale formation in Emu Bay, South Australia, by John Paterson of the University of New England in Australia and his colleagues. Until the team’s discovery, compound eyes had been observed only in creatures that have exoskeletons, which suggested—wrongly it now seems—that compound eyes evolved alongside exoskeletons.