Fossilized seashells’ true colors revealed

Under natural light, fossilized seashells appear devoid of color (top row). But under ultraviolet light, they appear bluish and patterns emerge (second row). Fluorescence hints at the presence of dark pigments, so reversing the UV images reveals what the shells probably looked like millions of years ago (third row).

Jonathan Hendricks

By Helen Thompson

April 2, 2015 at 12:00 pm

To the naked eye, fossilized seashells lack the colorful patterns of their living counterparts. But ultraviolet light can reveal some of the shells’ hues.

Jonathan Hendricks of San Jose State University in California examined 4.8-million- to 6.6-million-year-old cone snail shells from the Dominican Republic. Under UV light, organic compounds in the shells fluoresce (middle row) — though it’s unclear exactly which compounds are fluorescing.

Hendricks then re-created the shells’ pigmentation (bottom row), compared the patterns and identified snail species. Out of 28 species, 13 are previously unknown, Hendricks reported April 1 in PLOS ONE.