Stunning fossil trapped in amber reveals previously unknown species that lived during the time of dinosaurs

 

When dinosaurs roamed the Earth, their environment was very different from today's world. But there were  some similarities. And now scientists have confirmed a new fact: during the late Mesozoic era, a variety of fireflies lit up the night. The discovery comes from the fossil of an ancient species of firefly  trapped in 99-million-year-old Burmese amber from northern Myanmar, first discovered in 2016. The beetle is only the second firefly species identified from the Mesozoic era. In a July 2022 study, scientists estimated that fireflies evolved airborne bioluminescence, or the ability to emit light while flying, at least 100 million years ago. They analyzed the first Mesozoic glow-worm fossils described in 2015. However, experts say it's hard to determine exactly how glow-worms evolved and their bioluminescence, as glow-worm fossils from this period are hard to obtain because glow-worms' soft bodies aren't well preserved in the fossil record.  A recently identified species called Flammarionella hehaikuni could help researchers better understand the early evolution of fireflies and this feature, according to a study published Sept. 11 in the journal Proceedings of the Royal Society B: Biological Sciences. "This fossil helps fill a gap in our understanding of the evolutionary history of  lampyroid beetles (which include fireflies), showing that key features such as abdominal light-emitting organs have remained unchanged since the mid-Cretaceous," said Professor Chengyang Kai, lead  author  of  the study. "How amazing that dinosaurs once saw fireflies flying at dusk," he wrote in an email to the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Beijing.

Fireflies in the Land of Dinosaurs When Tsai first saw the firefly fossil in 2016,  he thought the beetle was a type of click beetle from the  family Elateridae, due to the fossilized insect's distinctive toothed antennae. This is similar to another species Tsai identified in Burmese amber in 2021. Fireflies do not have them. But when he re-examined the unusual fossil described in the new study in late 2022, Tsai noticed that the  light organ, a characteristic of fireflies, was well preserved. There are 10  species of ancient fireflies known only  from fossils, said Dr. Oliver Keller, a specialist in research museum collections at the University of Michigan in Ann Arbor who studies the systematics and taxonomy of fireflies. "The importance of this discovery lies in the rarity of firefly fossils  from this era," Keller said in an email. Because only one other Cretaceous firefly species has been identified so far, "we can use this new species  to revise (the July 2022 study) and more precisely date firefly evolution in light of  the new findings," he added. Keller was not involved in the new study or the 2022 study.  Fireflies glow for a variety of reasons, but most commonly as a defense mechanism and  to communicate and attract mates. It's hard to guess what lightning looked like 100 million years ago, but it could have been similar to what we see today, Keller said. The study's authors named the beetle in honor of French astronomer Camille Flammarion and amateur collector Haikun He,  who  donated several other amber samples to the researchers, according to the study. Types of fireflies There are more than 2,000  species of fireflies in existence today, according to the Natural History Museum in London. Study co-author Dr. Robin Kundrata said he suspects the newly discovered ancient firefly species may belong to the subfamily Luciolinae, which currently includes about 450 species, based on the arrangement of the light-emitting organs on the insect's abdomen. However, no living species of the Luciolinae family has the distinctive antennae that this fossil had, and the study led the authors to suspect that antennae may also differ depending on the sex of the insect. The newly identified fossil belongs to a female.

In addition, Kundrata stated in an email that the firefly fossil, which is less than one centimeter (0.4 inches) long and is morphologically distinct from the other specimen that was discovered in 2015, demonstrates that the light organs of Mesozoic species were more diverse than previously thought while still being comparable to those of modern fireflies.

According to the authors, it is their hope that additional firefly fossils from the Mesozoic will emerge in order for scientists to gain a better understanding of the bioluminescent beetles' enigmatic origins.

“Recent research suggests that fireflies originated during the Mesozoic Era, though the precise time period during which they originated is still a mystery. Kundrata stated, "Future discoveries may reveal additional information regarding their diversity and morphology." We would welcome the discovery of fossil larval specimens from the Mesozoic because there is no information about fireflies' immature stages from their early evolution.