crane fly fossil
crane fly fossil

Image of the Day: Fossilized Eyes

Both modern and ancient crane fly eyes contain eumelanin, a light-screening pigment.

Nicoletta Lanese
Aug 20, 2019

ABOVE: Fossil crane fly from the 54-million-year-old Fur Formation of Denmark, measuring 50 mm from wing tip to wing tip

An analysis of 54-million-year-old fly eyes revealed the oldest known record of a pigment thought to shield arthropod eyes from harmful light, researchers reported August 14 in Nature. The crane fly fossils were collected from a geological formation in Denmark known as the Fur Formation, and sport multifaceted compound eyes. The researchers compared the ancient crane fly to modern specimens and found that both contain eumelanin, a pigment that protects photoreceptors from light. 

The head of a 54-million-year-old crane-fly from the Fur Formation of Denmark, whose eyes measure 1.25 mm across at their maximum width

The fossilized eyes, but not modern ones, showed signs of calcification over the lenses, which the team suggests developed during the preservation process. The finding refutes previous hypotheses that some extinct arthropods developed calcified eyes during life, rather than as a result of fossilization.

J. Lingren et al., “Fossil insect eyes shed light on trilobite optics and the arthropod pigment screen,” doi:10.1038/s41586-019-1473-z, Nature, 2019. 

Nicoletta Lanese is an intern at The Scientist. Email her at