Our class discussion yesterday reminded me of a paper I came across that was recently published in Nature. It discusses possible coloration of an ancient leatherback turtle, an ichthyosaur, and a mosasaur. The researchers found that the ancient reptiles' skin likely contained eumelamin (melanin that produces brown/black coloration). The extinct leatherback turtle and mosasaur may have even been countershaded! Comparisons to modern marine organisms, such as the extant leatherback turtle, make it seem likely that these animals were dark colored or countershaded and could provide potential insights as to why these animals may have been colored this way. The article is very interesting and totally worth reading! Here's a link for anyone interested! There's a link to a PDF under the author list if the images don't show.