China has about 3 440 000 km² of karst terrain (erroded limestone with numerous caves), about a third of the country's total area, including tens of thousands of caves, and a correspondingly large number of cave-adapted organisms. Yunnan Province, in southwest China, is home to about 110 900 km² of karst, mostly in the east of the province, and contains about 15% of the cave-adapted species described from China. Pseudoscorpions are a common part of many cave bioms, including those of China, where there are currently 33 described species of cave-dwelling pseudoscorpions, eight of them from Yunnan Province.
In a paper published in the journal ZooKeys on 20 April 2022, Yanmeng Hou of the Key Laboratory of Zoological Systematics and Application at Hebei University, Zhizhong Gao of the Department of Biology at Xinzhou Teachers University, and Feng Zhang, also of the Key Laboratory of Zoological Systematics and Application at Hebei University, describe two new species of Pseudoscorpion from Yunnan Province, China.
The first new species is placed in the genus Tyrannochthonius and given the specific name pandus, meaning 'curved' in Latin, in reference to the curved chelal finger (part of the feeding apparatus) of this species. This species was discovered in Biyu Cave, a tourist site within the Ancient Alu Cave National Park in Luxi County.
Tyrannochthonius pandus is a moderately-sized cave-dwelling Pseudoscorpion, with males reaching about 1.41 mm in length and females 1.67 mm. It lacks eyes or eyespots. The anterior margin of its carapace is gently serrate, the epistome is small, pointed and triangular, with two hairs flanking its base. Another two hairs are present on the posterior margin of the carapace, and two more on each of the first three tergites (body segments), however there are no chemosensory hairs on the back of the chelal hands. The chelal fingers distinctly curved in dorsal view, with numerous large, gently curved, well-spaced teeth.
The second new species described is placed in the genus Lagynochthonius and given the specific name laoxueyanensis, meaning 'from Laoxueyan', in reference to Laoxueyan Cave, where it was discovered.
Lagynochthonius laoxueyanensis is another moderately-sized cave-dwelling Pseudoscorpion, with males reaching about 1.78 mm in length, and females 2.00-2.05 mm. It has elongate appendages and a carapace without eyes or eyespots. The anterior margin of the carapace is thin and finely denticulate. The epistome is pointed and small being roughly triangular in shape. There are two hairs on the posterior margin of the carapace, and another two each on the first two body tergites. The pedipalps are slender, the femur 8.54 times longer than it is broad, the chela is 7.71 times longer than it is broad, the chela fingers are gently curved in dorsal view and the fixed finger has a modified accessory tooth on dorso-antiaxial face.
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