A light in the dark: a mid-Cretaceous bioluminescent firefly with specialized antennal sensory organs

The beetle superfamily Elateroidea comprises the most biodiverse bioluminescent insects among terrestrial light-producing animals. Recent exceptional fossils from the Mesozoic era and phylogenomic studies have provided valuable insights into the origin and evolution of bioluminescence in elateroids.

The fossil possesses deeply impressed oval pits on the apices of antennomeres 3–11, representing specialized sensory organs likely involved in olfaction.

The light organ near the abdominal apex of Flammarionella resembles that found in extant light-producing lucioline fireflies. The growing fossil record of lampyrids provides direct evidence that the stunning light displays of fireflies were already established by the late Mesozoic.