The prehistoric animal kingdom was a riot of colors, from iridescent-feathered dinosaurs to jet-black ink excreted by Jurassic squid relatives. Like modern-day animals, ancient species' hues helped them communicate, camouflage and even regulate body temperature. But reconstructing these colors today is a challenge because compounds and structures that color animals' skin, fur and feathers usually degrade or change during fossilization. Experts have developed methods to reliably detect structures and pigments related to dark colors like the black and brown of feathered dinosaurs, but other shades (like the yellow and reddish-orange made by pigments called pheomelanins) have been especially hard to pin down.

Now a team of scientists has filled in that missing chunk of the prehistoric palette by developing the first reliable test to detect these gingery colors in fossils. “Pheomelanin is clearly an elusive pigment, and these findings will absolutely help us to detect evidence of ginger pigments in other fossils,” says the study's lead author Tiffany Slater, a paleobiologist at University College Cork in Ireland. The results were recently published in Nature Communications.