Bioluminescent beetle trapped in amber

[Still Waters]

Trapped in amber for ~100 million years, an exceptionally well-preserved, light-producing beetle sheds light on the diversification of bioluminescent beetles in the Cretaceous period and provides the missing fossil link between fireflies' living relatives.

With over 3,500 described species, light-producing beetles are the most diverse bioluminescent terrestrial animals. Fireflies, fire beetles, glow-worm beetles and their kin use light to ward off predators, attract mates, and some females even use it to attract unsuspecting males to eat. Historically, despite their diversity, the evolution of bioluminescence in beetles has been poorly understood.

https://phys.org/news/2021-01-amber-encased-fossil-evolution-bioluminescent-insects.html

https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2730