Micro-Fossils Reveal Dinosaur Colors and Ancient Sea Life

J. Vinther/Yale

It's been a good week for people who look through microscopes at fossils. First off, Scientific American told us about some German scientists who discovered evidence of 400-million-year-old life trapped in seawater trapped inside volcanic rock.

Far more buzz circled around the second report: that we may be able to figure out what color dinosaurs and ancient birds were. This means that one day, paleontologist-artists may have to stop dreaming up rosy purples and outlandish greens to clothe their dinosaurs in (remember Mark Witton's lovely pterosaurs a few posts ago?).

Is there any ephemeral detail that scientists can't discover about long-dead creatures through clever chemistry? They've figured out the diet of an extinct seabird, learned about Aztec travels from records in exhumed teeth, and now they've put back together the stripes on a 100-million-year-old bird.

The evidence sat in front of them for years in the form of a powdery residue on some fossils. It was long thought to be the meaningless remains of carrion-eating bacteria, but Yale graduate student Jakob Vinther's electron microscope revealed the powder looked exactly like the pigment-bearing sacs that occur on modern-day feathers. Nowadays, those sacs are full of melanin which give birds colors ranging from black to russet brown.

Though the work was done on fossil birds, the scientists report that similar residues from dinosaur scales and the hair of ancient mammals may reveal their colors as well. The researchers were also careful to point out that the residues didn't contain any intact melanin (unlike the T. rex discovered in 2005 with actual protein still preserved inside a massive thigh). A hundred million years is a long time, after all.

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