Dinosaurs were accompanied by the flickering presence of fireflies.
In the movie "Jurassic Park," scientists revitalize dinosaurs utilizing the ancient blood of a mosquito entombed in amber. In reality, researchers are intrigued by such fossils, primarily focusing on the insect itself, especially if it's as extraordinary as the luminescent worm that roamed the Earth millions of years ago.
Dinosaur eyes might have been graced with the spectacle of luminescence, given that bioluminescence was likely prevalent in insects during the Cretaceous era. A recently unveiled insect sealed within amber dates back around 99 million years. Scientists declare this discover to be a glow worm (Lampyridae). They detail their findings in the journal "Proceedings B" of the British Royal Society.
The newly identified beetle showcasing light-emitting organs is named Flammarionella hehaikuni. It's believed to be a female ancestor of the modern subfamily Luciolinae, asserts the research team led by Chenyang Cai from the Nanjing Institute of Geology and Paleontology in China. The light organ situated near the beetle's abdomen's tip bears a striking resemblance to the light-producing organs of current fireflies.
Abundant Glow Worm Discoveries in Amber Deposit
This is the second glow worm species from the Cretaceous period to be unearthed, which stretched from 145 to 66 million years ago. Both a feathered firefly and a luminous beetle belonging to the fossil family Cretophengodidae have also been discovered from this timeframe. All were found in a 99-million-year-old amber hailing from the Hukawng Valley in northern Myanmar.
As the first author explains, these fossils originate from the same amber deposit and epoch, and they showcase a variety of morphological adaptations related to bioluminescence. This suggests that the evolutionary process during that period produced numerous light-emitting organs.
Research indicates that bioluminescent beetles might have emerged between the late Jurassic and early Cretaceous periods. The proliferation of well-documented Lampyrids is evidence that the radiant light shows of various glow worms were already in existence during the Cretaceous period.
Glowing Small Fireflies in Central Europe Today
More than 2,000 species of fireflies have now been recognized - with only a handful inhabiting Central Europe. In certain species, it's only the male counterparts who can fly, whereas not all species produce light in both sexes. In Central Europe, you'll inevitably encounter glowing flying male small fireflies (Lamprohiza splendidula).
The light organs are always located at the rear end. Green light is the result of a chemical reaction: Luciferin transforms into oxyluciferin by the enzyme luciferase. During this transition, energy is released as light. Experts surmise that the light organs serve for mate searching or communication.
First author Chenyang Cai posits that bioluminescence in beetles might have initially been a defensive mechanism. "The emitted light might have acted as a warning signal to potential peril, signaling the beetles' toxicity or inedibility to predators." This conjecture is supported by the observations that many beetles already possess light organs in their larval stages, long before reaching sexual maturation, suggesting a purpose beyond courtship.
The recently discovered beetle measures around 8.5 millimeters in length, 2.9 millimeters in width, is dark brown, and is extensively haired. Its most distinctive trait is its long, strikingly serrated antennae. This new species varies significantly from modern Luciolinae, whose antennae usually have thin and brief threads, according to the research. However, Flammarionella is still assigned to this subfamily, with the expectation that more well-preserved glow worms from the Cretaceous period will be discovered soon.
Lead author Chenyang Cai attributes this confidence to the abundance of resin-producing trees in Cretaceous forests. Resin safeguarded the trees and simultaneously entombed numerous insects. "The resin ensnared these organisms rapidly and shielded them from decay, weathering, and scavengers, ultimately resulting in exquisitely preserved fossils."
The study adds that the glow worm exhibits peculiar transformations to its antennae. The shallowly imprinted oval depressions at the tips of the antenna segments could have aided in scent detection. "This type of sensory organ in the antenna has not been documented in glow worms before. Similar pits can be found in various insect orders and are utilized as scent organs."
The dinosaurs might have witnessed the luminescence of these ancient glow worms, as bioluminescence was prevalent in insects during the dinosaurs' era, the Cretaceous period. The recently discovered beetle, Flammarionella hehaikuni, is believed to be a female ancestor of modern fireflies, further indicating the presence of glow worms during the dinosaur era.
