Fossil Image CC BY-NC 4.0
Autumn Colored Fossil Leaf
Who has not seen stunning displays of fall leaves, unless you live at too small or large of a latitude? By late summer, trees have sensed the shortened days, and begin turning off some genes and turning off others, which in turn beginning shutting down photosynthetic energy production. Turning water and carbon dioxide into energy by photosynthesis requires a lot of the green pigment chlorophyll. Essentially, the tree turns off the chlorophyll that is so abundant that most leaves are green during the growing season. As the chlorophyll is used up and not replaced, remaining color pigments always present come to dominate. One of those is beta-Carotene (lower left molecule), the strong orange pigment that makes carrots and pumpkins orange, and your skin orange too if you eat enough carrots and pumpkins. Hence, the orange in autumn leaves.
Fossil leaves are normally brown, though they can be quite detailed showing venation. The fossil leaf above is uncommonly colored, displaying autumn-like colors, but for entirely different reasons than live plants. During fossilization, organic material is replaced with minerals, and the fossil then displays the corresponding mineral colors. The red coloration above is likely due to the presence of iron.
The fossil above is a 2 inch long, 50 million year old Eocene elm leaf from the Tranquil Shale in British Columbia, Canada.
found @ 27 likes ON 2019-03-10 06:43:56 BY ME.ME