When you think of the color scheme sported by the prehistoric world of dinosaurs, green and brown generally come to mind.
But more and more research has shown that millions of years ago, bright and vivid colors were everywhere in nature, just like they are today. The latest test: 99 million year old insects caught in amber with incredible colors of purple, blue and metallic green.
One of the reasons why it is so difficult to know the colors of prehistoric creatures is due to what remains of them: a fossilized bone cannot communicate what color the animal was. But lately, scientists have developed pigments from fossilized feathers; or, in the case of this latest study, he used Burmese amber to scan the world of ancient colors.
“The type of color preserved in amber fossils is called structural color. It is caused by the microscopic structure of the animal̵
“The surface nanostructure scatters the light of specific wavelengths and produces very intense colors. This mechanism is responsible for many of the colors we know from our daily lives.”
Structural color is what makes peacock feathers and butterfly scales appear iridescent; in this case, it was created from the outer cuticle of the insect’s exoskeleton.
The team collected 35 specimens of amber containing ancient insects that also possessed these intense structural colors.
The vast majority of the specimens were cuckoo wasps (Chrysididae family) or calcid wasps (part of the superfamily Chalcidoidea). The amber-covered creatures showed their metallic bodies blue-green, yellow-green, blue-violet or even vibrant.
Interestingly, the amber cuckoo wasps (see, for example, the first green insect in the series of images above) had almost the same color as the cuckoo wasps that are around today.
“The color displayed by fossils can often be misleading because the nanostructures responsible for staining can be changed during fossilization. However, the original color of the fossils can be reconstructed using theoretical models,” writes the team in their document.
“The calculated reflectance peaks correspond to the observed metallic bluish-green coloration of the mesopleuron of our studied wasp, confirming that extremely fine nanostructures can be preserved in Mesozoic amber.”
The team also thinks they have an explanation as to why only some amber insect fossils retain the coloring of the animals inside.
After traversing the exoskeleton of two vibrating wasps and a relatively boring fossil, they found that in the boring sample, the cuticular structures that create the structural colors are damaged. In colored fossils, insect exoskeletons and light-scattering nanostructures were still preserved.
As we admire the findings, it is important to note that the paleontology community is currently debating whether the scientific information that can be collected from these specimens collected and sold in Myanmar is worth the price of potential human consequences, including the persecution of ethnic minorities.
In recent years, amber has given us incredible Cretaceous creatures. These animals lived almost 100 million years ago and the findings include the skull of the smallest dinosaur, some small frogs, a bird with an oddly long finger and many, many others.
The research was published in Proceedings of the Royal Society B: Biological Sciences.