Fireflies learned to glow against predators 100 million years ago

In the wilderness in the middle of summer, the fireflies flicker and extinguish, like a mysterious lamp. Usually, only young and female fireflies glow, which is a courtship signal. A very small number of male fireflies also use flashes of light for defense.

Recently, the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, in collaboration with Palatsky University in the Czech Republic, the University of Bristol in the United Kingdom and Sun Yat-sen University, discovered an "old ancestor" of fireflies from Burmese amber: chalk fluorescent fluorescent family. The discovery of this new taxon is of great significance for the study of the origin and evolution of bioluminescence in the family Percussion. The results were published online on January 20 in the Proceedings of the Royal Society – Series B.

Among terrestrial animals, the species that can perform bioluminescence are the most common species in the family Percussion (fireflies and their close relatives). Most of the species of the luminous percussion family belong to the "fluorescent family", including the fluorescent family, the fluorescent family, the female fluorescent family, and the Huaguang percussion family.

In this branch, except for the most basic Family of Huaguang, the bodies of the Family Fireflies, the Family Of Fluorescent, and the Family of Female Fluorescent Are relatively soft, and the females of some taxa also have juvenile persistence, which makes it difficult for species of this group to be preserved as fossils. With the exception of the Fluorescence family, which has a record of fossils in Cretaceous Burmese amber and some Cenozoic strata, no fossils have been officially reported in other taxa.

Researchers have found a relatively well-preserved male specimen of Aza chalk light fluorescent fireflies in Burmese amber in the middle Cretaceous period (about 100 million years ago). The chalk fluorescent fluorescent antennae have 12 segments and are biliform, similar to the living light fluorescent family. However, the forethia of the cretaceous fluorescent firefly is more developed, the elytra completely cover the abdomen, and 6 segments of the abdomen are visible in the abdomen, which is different from the light fluorescent family and the closely related female fluorescent family. Based on its morphological characteristics, the researchers speculate that chalk fluorescent fluorescent may belong to the basal taxon of the evolutionary branches of the family Photofluorites + Estrogenaceae.

"The fossils we found are a relatively primitive type, which can be understood as the ancestral type of fireflies." Cai Chenyang, an associate researcher at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, told reporters.

Chalk fluorescent fluorescence sections 1-3 have a light-colored bright area on the visible web, which the researchers believe is a light-emitting organ. In the Cretaceous Period, ants, frogs, early birds, etc. flourished rapidly, and they were all potential predators of Cretaceous fluorescent fireflies. The researchers speculate that the luminous organs in chalk fluorescent fireflies may be related to the defense against these predators.