An article published in the journal “Science Advances” describes the discovery of the oldest fossil remains of lepidoptera, the order of insects that includes butterflies and moths. A team of scientists analyzed soil samples in which Professor Paul K. Strother of Boston College previously identified fossil remains. The dating at about 200 million years ago indicates that those insects existed tens of millions of years before flowering plants, while many previous estimates suggested a possible coevolution between the two groups.
The lepidopterans, order Lepidoptera, make up a very large group of insects but the presence of fossils is poor compared to that of other insects. It’s a typical case in which paleontologists and in this case entomologists are forced to make estimates based on incomplete data with very different results because of the existing unknowns.
In 2012 Professor Paul K. Strother was in Schandelah, in Lower Saxony, Germany, where he examined samples of sedimentary rock dating from the Triassic-Jurassic boundary. At that time, about 200 million years ago, there was a mass extinction that could be associated with intense volcanism phenomena coinciding with the fragmentation of Pangea, the supercontinent that then comprised almost all the lands.
According to estimates, about 35% of the living species was wiped out during that mass extinction, on the contrary the indications suggest that lepidoptera not only didn’t become extinct but that they diversified a lot in the following period. Something like this happened to dinosaurs so it’s possible that this mass extinction led to environmental conditions in which lepidoptera managed to thrive.
After the discovery of the fossil remains of lepidoptera, Professor Paul K. Strother began a thorough research together with other scientists such as Timo van Eldijk and Bas van de Schootbrugge of Utrecht University. The fossils show characteristics typical of their taxonomic order in their scales but their descendants are known among other things in their connection with flowering plants, which 200 million years ago didn’t exist yet.
These new discoveries indicate that the early lepidoptera, belonging to the Glossata suborder, were linked to Gymnosperms. These insects’ mouth apparatus evolved to feed on pollination droplets, typical secretions of various plants in that group. Only long afterwards, with the appearance of flowers, lepidoptera adapted to Angiosperms, another large group of plants.
This research obtained new information on the evolution of lepidoptera and offers new ideas for research. It brings a greater understanding of the relationship of butterflies and moths with different groups of plants throughout their history but also of their evolution following a mass extinction. This could help to understand how they can evolve in the future as a result of the environmental changes that are currently taking place.