Tanaka, Zhou, Zhang, Siveter, and Parker, 2017, Rods and cones in an enantiornithine bird eye from the Early Cretaceous Jehol Biota: Heliyon, v. 3, e00479
What’s it about?
A fossilized bird (as yet unidentified except to know it’s an enantiornithine bird) was found to have well-preserved structures in its eye, especially a fossilized retina. Using various methods (including scanning electron microscopy and specialized light microscope techniques) the authors were able to not only identify rods and cones in the retina, but were also able to determine that this bird was able to see in color.
Why does it matter?
The ability to see color not only informs scientists about what the bird could see, but also suggest that there were colorful organisms present at the time this bird was alive.
Why did I read this?
The preservation of soft tissues (like a retina) is exceedingly rare in the fossil record. How the authors distinguished rods, cones, and little droplets of oil is a little mysterious to me, but their ability to do so in both fossil and modern examples is convincing.