Nearly all fossils are stripped of their original color. But as a new study from Irish paleontologists shows, that doesn’t necessarily mean the colors aren’t still there. You just have to know where to look.
Normally, fossils are devoid of any color, forcing paleontologists to make educated guesses about their specimen’s actual appearance. In some rare cases, melanin (a pigment that gives color to skin) manages to retain its organic nature over long timescales, revealing dull pigments of browns, blacks, and muddy reds. No other pigments are able to survive fossilization.
But where there’s a will, there’s a way. Paleontologists from the University College Cork in Ireland analyzed a 10 million-year-old snake fossil found preserved in calcium phosphate. They found that the colors of the long-extinct snake could still be gleaned even when the actual colors aren’t there any more. This latest study now appears in Current Biology.
The researchers mapped the location and shape of each pigment cell on the snakeskin fossil. Depending on the specific shape of the pigment cell, they were able to derive certain colors, including yellows, greens, blacks, brown, and even iridescence. To be clear, the pigments are long gone, but the cell shapes—which are specific to each type of pigment—still retain enough information to reconstruct the former colors. “For the first time, we’re seeing that mineralized tissues can preserve evidence of color,” lead researcher Maria McNamara said in a statement.
According to McNamara’s analysis, the 10 million-year-old snake, a member of the Colubridae family, featured three types of pigment cells in various combinations. Its skin contained melanophores, xanthophores, and iridophores. Translated to color, this means the snake was a mottled green and black, with a pale underside. The scientists suspect that this particular color scheme allowed the snake to camouflage itself during daytime.
This study suggests that other similar fossils may yield similar clues. As McNamara said, “It’ll mean re-evaluating a lot of specimens that might have been overlooked.”