A collection of spider fossils were discovered in South Korea, including two featuring eyes appearing to glow, according to a study.
The fossils were discovered in an area of shale rock in South Korea called the Jinju Formation, according to the study published last month in the peer-reviewed Journal of Systematic Palaeontology.
Researchers say two of the fossils of the spider family Lagonomegopidae, believed to have lived between 110 and 113 million years ago, have reflective eyes helpful for hunting at night.
The study said this is the first preservation on the fossil record of a spider’s tapetum, the structure inside the eye allowing it to reflect light.
“Because these spiders were preserved in strange slivery flecks on dark rock, what was immediately obvious was their rather large eyes brightly marked with crescentic features,” said Paul Selden, a professor of geology and director of the Paleontological Institute at the University of Kansas’ Biodiversity Institute and Natural History Museum, in a statement.
The study was completed in collaboration with a researcher at the Korea Polar Research Institute and a high school teacher with the Daejeon Science High School for the Gifted in South Korea who discovered the fossils.
Typically, spiders and other insects are preserved in amber because their bodies are softer, unlike animal fossils comprised of harder substances such as bones or teeth.
Selden said researchers are still trying to figure out how the spiders stayed preserved in the shale without decaying.
“It has to be a very special situation where they were washed into a body of water,” he said. “Normally, they’d float. But here, they sunk, and that kept them away from decaying bacteria — it may have been a low-oxygen condition.”
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