Chalk amber fossils shed light on the evolution of bioluminescence in insects

Bioluminescence has fascinated people since ancient times. Most of the organisms that can produce their own light are insects, especially fireflies, glistening worms, and their relatives.

Although the chemistry that gives some insects the ability to glow almost magically is now highly valued, little is known about how these signals evolve.

New research by a team of scientists led by the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS) has provided new insights into the evolution of this potential. His research focused on the newly discovered family Cretophengodidae, a Chalk amber fossil that illuminates the bioluminescence of insects. Their work was published Affairs of the Royal Society B January 20, 2021.

“The newly discovered fossil, preserved in living amber in the amber, represents an extinct relative of fireflies and small families. Raqoftalmidae and PhengodidaeHe said. Paleontologist and lead author LI Yanda, a scientist from NIGPAS and Peking University.

Cretophengodes azari derived from Middle Cretaceous Burmese amber and existing relatives. Credit: NIGPAS

The amber from northern Myanmar is about 99 million years old and dates back to the golden age of dinosaurs. “The new fossil is very well preserved; even the organ of light in the abdomen is intact, ”said Dr. CAI Chenyang, Associate Professor and Researcher at NIGPAS University of Bristol.

“Fossils show that some insects already shone in Cretaceous 99 million years ago. We think that light production first developed as a defense mechanism to protect the insect from predators in soft and sensitive larvae. He was later picked up by an adult and chose to perform other functions, such as finding mates, ”said Robin Kundrata, an elateroid insect specialist at Palacky University in the Czech Republic.

Cretophengodes azari’s systematic position. Credit: NIGPAS

About 386,000 species have been described, and perhaps more than a million species are still awaiting discovery, with insects being the most diverse group of animals. Most light-producing insects belong to the giant super family Elateroidea, with about 24,000 species. It is one of the most heterogeneous groups of insects and has always posed challenges for entomologists, especially since important anatomical innovations have been independently obtained in repeatedly unrelated families.

“The discovery of a new extinct elateroid beetle family is important because it helps shed light on the evolution of this surprising but fascinating group,” said Eric Tihelka of the School of Earth Sciences and a participant in the study.

For more information on this study, read the Lost Fossil Link of 100 Million-Year-Old Beetle Fireflies.

Reference: “Cretophengodidae, a new Cretaceous beetle family, sheds light on the evolution of bioluminescence” Yan-Da Li, Robin Kundrata, Eric Tihelka, Zhenhua Liu, Diying Huang and Chenyang Cai, January 20, 2021, Affairs of the Royal Society B.
DOI: 10.1098 / rspb.2020.2730