New pseudoscorpions with dragon-like jaws discovered in a South Korea cave
Pseudoscorpions may lack the pointy, poisonous tail of their more famous desert-dwelling cousins, but their crab-like front pincers still make them look quite formidable. Now, these small, sometimes overlooked arachnids are getting a closer look. Four new species of these tiny arachnids have been uncovered in the dark caves of South Korea. They have jaws like dragons and are even completely blind, according to a study published July 9 in the journal PLOS One.
What are pseudoscorpions?
Pseudoscorpions are harmless to humans and related to spiders and “real” scorpions. They eat small insects, other arthropods, and larvae. They live in many habitats, and are often found in tiny crevices, under tree bark, and in humid environments full of leaf litter and moss. They also can be found in dark, damp places like caves.
Since South Korea is home to hundreds of unexplored caves and close to countries with several pseudoscorpion species, arachnologists were curious what pseudoscorpions could be lurking in these limestone cave systems and lava tubes spread across two extensive mountain ranges.
A pseudoscorpion from the genus Paratemnoides in South Korea. CREDIT: Kyung–Hoon Jeong.“Pseudoscorpions are awesome animals,” Kyung–Hoon Jeong, a study co-author and arachnologist at South Korea’s Jeonbuk National University, tells Popular Science. “We can divide pseudoscorpions in two types–basal lineage and modern lineage.”
The basal lineage cannot move far, making them endemic wherever they live. Scientists can use their distribution to learn more about their geographical secrets, according to Kyung–Hoon.
The modern lineage does a little bit more. They hitchhike on other animals and make houses out of their silk.
Blind dragons
Only five pseudoscorpion species have been recorded from caves in South Korea, compared to the hundreds that have been documented in countries like China. This study brings that total up to nine.
“Many people have believed there is only one species (Spelaeochthonius dentifier) distributed in Korea. However, our result was totally different,” says Kyung–Hoon.
The newly discovered species are named Spelaeochthonius dugigulensis, S. geumgulensis, S. magwihalmigulensis, and S.yamigulensis. Those in the family Pseudotyrannochthoniidae are often referred to as “dragon pseudoscorpions,” due to their large front appandages that resemble dragon jaws.
All four new species strongly adapted to cave living and were only found in a single cave system. These new additions have an orange to brown color. They are mostly blind, and have dragon-like jaws that can clamp down on the smaller organisms. However, they are not all the same.
Habitus of Spelaeochthonius dugigulensis. A. Holotype male, dorsal view; B. Holotype male, ventral view; C. Paratype female, dorsal view; D. Paratype female, ventral view. Scale bar: 1 mm. CREDIT: Jeong et al., 2025, PLOS One“Each species in the cave has big differences, both in morphology and genetically,” says Kyung–Hoon. “Additionally, their relevance is supported by the connection between Korea and Japan.”
This indicates that these pseudoscorpions likely were more widespread in East Asia before the Sea of Japan formed between the countries roughly 28 to 13 million years ago. They then likely traveled between the two over water, hitching rides on other organisms.
While the team is still studying these new arachnids, their perfect adaptations to cave life means that they can only survive if their habitat stays intact. Pollution and climate change could threaten these small and endemic animals, according to Kyung–Hoon.
“Our study highlights the conservation value of pseudoscorpions, we believe that the interest of this small animal could bring attention to their habitats and environment,” he concludes.
