Fossilized remains of ancient species of animals can help paleontologists and scientists discover the hidden secrets regarding the existence of vivid species who lived on the Earth more than 100 million years ago. This allows the scientists to ascertain the structure, characteristics and other features of these species. A team of international researchers comprising of Chinese, German, & British scientists recently underwent a successful research in order to discover the color of a 200-million-year-old insect for which, the fossil was found trapped in amber.
The study was conducted by scientists from Chinese Academy of Sciences, Nanjing Institute of Geology and Palaeontology (NIGP) and other researchers hailing from the UK, and China studied the 200-million-year-old fossilized remains of insect for which, the research paper were published in the journal Science Advances. Researchers undertook to the task of determining the color of a Trichoptera fossil that was found trapped in the Burmese amber. The challenge was to determine the color which is an extremely difficult feat to achieve since the insect showed no signs of colors through pigmentation.
As per the study, the insects got its colors through structural arrangements which are common for Lepidoptera, an order which covers moths and butterflies. These structures allow the insects to have rather distinguishing and diversifying vivid colors. As said, structural colors which are the result of structures made to allow the selective wavelength of incident light to scatter and produce vivid color is visually more stunning than the color produced via pigmentation. Moreover, these structural colors are multifunctional as it also allows the insects to perform functions such as crypsis, aposematism, and sexual signaling.
The international team of researchers studied the Jurassic Lepidoptera hailing from China, Kazakhstan, Germany, and Britain along with the Trichoptera retrieved by Burmese amber dating back to the mid-Cretaceous period. They employed the use of optical modeling to study the scale arrangements where the Jurassic lepidopterans were found to exhibit type-1 bilayer scale vestiture which comprises of a lower layer of small fused ground scales and an upper layer of large fused cover scales. Further, the fossil was found to have herringbone structure covering its upper layer which is a V-pattern weaving structure i.e. the same V-shaped structure repeated at regular intervals which results in structural colors.
Also, researchers found periodicities or structures that periodically repeated over ranging between 140 to 2,000 nanometers where the incident light falls on it and scatters a selected wavelength of light. The study found out that these insects would have produced metallic bronze to gold on color in its wings due to these tiny photonic structures as elaborated above.
Researchers were able to find evidence about the early evolution of insects in the order of lepidopterans scales. The model will be subjected to further studies that will peep deep into the complex evolutionary process in moths and butterflies under lepidopterans order.