**Ancient Firefly Fossil Illuminates Evolutionary History**

Scientists have long speculated about the world during the dinosaur era, and now, a fascinating discovery reveals that diverse firefly species once lit up the night skies of the late Mesozoic. A fossilized firefly, trapped in 99 million-year-old Burmese amber from northern Myanmar, is shedding new light on these ancient luminescent beetles.

The remarkable fossil, discovered in 2016, is only the second identified firefly species from the Mesozoic era. This find has tremendous implications for understanding the evolution of fireflies and their bioluminescent capabilities. A study published in September 2023 in the journal Proceedings of the Royal Society B: Biological Sciences reveals that this newly identified species, named Flammarionella hehaikuni, could significantly advance our knowledge of these ancient beetles.

Leading the study, Professor Chenyang Cai from the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences, noted the importance of the fossil in bridging gaps in our comprehension of the evolutionary history of lampyroid beetles. These beetles have had abdominal light organs since the mid-Cretaceous period, a trait that has remained consistent over millions of years. Cai marveled at the idea that "dinosaurs once saw fireflies flying at dusk."

Initially mistaken for a type of click beetle due to its unique serrate antennae, Cai revisited the fossil in late 2022 and confirmed its true firefly nature upon observing the well-preserved light organ. This discovery is significant, considering that firefly fossils from this period are rare due to the insects' soft bodies, which do not fossilize well. Dr. Oliver Keller, a research museum collection specialist at the University of Michigan, emphasized the fossil's rarity and its potential to refine our understanding of firefly evolution.

Modern fireflies, known for their glowing displays used in defense and communication, may not look very different from their ancient counterparts. While the precise appearance of their flashes 100 million years ago remains speculative, Keller suggests they might have been similar to those we see today.

The study commemorates French astronomer Camille Flammarion and collector Haikun He, who donated significant amber specimens, in naming the new species. With over 2,000 firefly species existing today, the newly discovered Flammarionella hehaikuni is hypothesized to be part of the Luciolinae subfamily, known for their abdominal light organs.

Unlike modern Luciolinae species, this ancient firefly possesses unique serrate antennae, which may have varied by sex. Its structure, under one centimeter in length, differs notably from the other Mesozoic firefly fossil identified in 2015, suggesting a greater diversity in early firefly light organs than previously understood.

Researchers are hopeful that more firefly fossils from the Mesozoic will surface, providing further insights into these enigmatic bioluminescent beetles. Study coauthor Dr. Robin Kundrata from Palacký University Olomouc in the Czech Republic highlights the potential for future discoveries to unveil not only adult but also larval stages of early fireflies, thus enriching our understanding of their ancient origins.