Infrared mapping resolves soft tissue preservation in 50 million year-old reptile skin. 2011. N. P. Edwards, e tal. Proc. B., published online before print March 23.
"The mapped distributions of organic compounds and trace metals in 50 million year old skin look so much like maps we've made of modern lizard skin as a check on our work, it is sometimes hard to tell which is the fossil and which is fresh."