A 99-million-year-old beetle shines light on the evolution of glowing insects

By Megan Marples, CNN

Updated 0001 GMT (0801 HKT) January 20, 2021

In this July 21, 2016 photo, fireflies light up a section of a forest in Mexico. At times, hundreds of the bioluminescent beetles will synchronize their lights, blinking on and off in perfect rhythm. Click through the gallery to see other bioluminescent organisms.
Photos: Bioluminescent fauna and flora
In this July 21, 2016 photo, fireflies light up a section of a forest in Mexico. At times, hundreds of the bioluminescent beetles will synchronize their lights, blinking on and off in perfect rhythm. Click through the gallery to see other bioluminescent organisms.
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Each year, Watasenia scintillans, or firefly squid, rise up from the deep waters off the coast of Japan to mate.
Photos: Bioluminescent fauna and flora
Each year, Watasenia scintillans, or firefly squid, rise up from the deep waters off the coast of Japan to mate.
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Tube anemone display multiple different colors, making them a popular feature of home aquariums.
Photos: Bioluminescent fauna and flora
Tube anemone display multiple different colors, making them a popular feature of home aquariums.
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Noctiluca scintillans or sea sparkle is a large, bioluminescent and nontoxic phytoplankton that causes the sea to glow. It is relatively common in Hong Kong, but it is uncommon to capture its iridescent glow on camera. It only appears when the water is disturbed or the ecosystem is out of balance.
Photos: Bioluminescent fauna and flora
Noctiluca scintillans or sea sparkle is a large, bioluminescent and nontoxic phytoplankton that causes the sea to glow. It is relatively common in Hong Kong, but it is uncommon to capture its iridescent glow on camera. It only appears when the water is disturbed or the ecosystem is out of balance.
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Sea creatures aren't the only thing that glow. Some fungi do, too. Omphalotus nidiformis or ghost fungus is primarily found in Australia. It uses a bioluminescence technique certain organisms have developed to create energy, in the form of light, through a chemical reaction.
Photos: Bioluminescent fauna and flora
Sea creatures aren't the only thing that glow. Some fungi do, too. Omphalotus nidiformis or ghost fungus is primarily found in Australia. It uses a bioluminescence technique certain organisms have developed to create energy, in the form of light, through a chemical reaction.
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The pelagic octopus or open-ocean octopus is mainly found in Hawaii. Documentary filmmaker Martin Dohrn developed a special camera to catch bioluminescence because he says it was "...designed to function at the very limits of animal vision, which is far beyond the limits of most cameras."
Photos: Bioluminescent fauna and flora
The pelagic octopus or open-ocean octopus is mainly found in Hawaii. Documentary filmmaker Martin Dohrn developed a special camera to catch bioluminescence because he says it was "...designed to function at the very limits of animal vision, which is far beyond the limits of most cameras."
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Does the fluorescent lizardfish glow to communicate with other fish? There is a light show in the ocean that you may not be able to see, but many fish can. The discovery of what is hidden from human eyes -- biofluorescence in 180 species of fish -- brings up this and many questions for researchers.
Photos: Bioluminescent fauna and flora
Does the fluorescent lizardfish glow to communicate with other fish? There is a light show in the ocean that you may not be able to see, but many fish can. The discovery of what is hidden from human eyes -- biofluorescence in 180 species of fish -- brings up this and many questions for researchers.
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Comb jellyfish, which evolved more than 500 million years ago, can emit and reflect light, according to the <a href="https://www.genome.gov/27551984" target="_blank">National Human Genome Research Institute</a>.
Photos: Bioluminescent fauna and flora
Comb jellyfish, which evolved more than 500 million years ago, can emit and reflect light, according to the National Human Genome Research Institute.
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Instead of only producing blue light like most other bioluminescent marine animals, the dragon fish emits a red light as well. Although red light doesn't travel as far, it lets the dragon fish see its prey undetected.
Photos: Bioluminescent fauna and flora
Instead of only producing blue light like most other bioluminescent marine animals, the dragon fish emits a red light as well. Although red light doesn't travel as far, it lets the dragon fish see its prey undetected.
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(CNN)Bioluminescent insects have long fascinated scientists, but little is known about how these animals got their light abilities. A 99-million-year-old beetle recently discovered by researchers, however, unlocks a piece of the evolutionary puzzle, according to a study published in The Royal Society journal.

The beetle, known by its Latin name Cretophengodes, was found fossilized in a piece of amber in northern Myanmar. The tropical location was full of insect life during the Cretaceous period, said study author Chenyang Cai, an associate professor at Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences in Beijing.
The Cretophengodes beetle roamed the tropical forests of Southeast Asia nearly 100 million years ago during the Cretaceous period.
The Cretophengodes beetle roamed the tropical forests of Southeast Asia nearly 100 million years ago during the Cretaceous period.