Fly fossils might challenge the idea of ancient trilobites’ crystal eyes

Fossil lenses from the 54-million-year-old insects raise questions about other species’ sight

crane fly fossil

Tiny, fossil crane flies found in Denmark have compound eyes (dark bulges in this specimen) with unusual lenses, renewing debate about how different extinct creatures — called trilobites — once saw the world.

René Lyng Sylvestersen

Fossil crane flies found in Denmark have crystals in their eyes — individual, see-through mineral pieces where the living eyes’ lenses once were.