Starfish and brittle stars may have evolved complex lenselike structures at least 79 million years ago to detect and evade shell-crushing and boring predators flourishing during the Mesozoic era.
Fossils from Poland show that some echinoderms had arm plates with arrays of closely packed bulges made of the mineral form of calcium carbonate. The bulges are similar to the structures that form microlenses in the living, light-sensing brittle star Ophiocoma wendtii, which evades predators quickly by wiggling into dark crevices, researchers report April 1 in Nature Communications.