Female Songthela longhui, one of three mesothelial spiders identified in China
Zhang Y, Chen Z, Li D, Xu X
Three new species of an ancient and secret spider group native to China’s Hunan province have been described. It has strange and primitive features not found in most of the spiders out there.
Most spider species on Earth today belong to one of two groups. Heavy-bodied mygalomorph spiders, such as tarantulas and the notorious venomous funnel web spider, and tens of thousands of Araneomorph spider species, many of which weave intricate, sticky webs. .
About 100 spider species belong to a third, less understood group, classified within the suborder Mesotheraea. When the Earth’s rainforests were filled with giant arthropods and the first reptiles, mesothelial spiders diverged from other spiders. Today, the only surviving family of mesothelial spiders retains some physical characteristics of the first spiders. It has a plate at the top and is split, like the buttocks of the . Their silk-spitting spinnerets are uniquely suspended below the center of their abdomens, rather than at the tail end.
All modern mesothelial spiders live in East and Southeast Asia, are about 1 to 2 cm long, and ambush prey through tubular burrows.
Xin Xu of Hunan Normal University, China, and her colleagues collected young mesothelial spiders in parks and villages in western Hunan and reared them to adulthood in the lab.
Researchers can use differences in the shape of spider sexual structures to distinguish closely related species. sontera. Species – sontera Anhua, sontera Ryuki and sontera Zhongpo – Named after the state location where it was discovered.
“[Mesotheleans] It’s a living fossil and generally rare,” says Sarah Cruz of the California Academy of Sciences in San Francisco. “We are learning that they are more diverse than once thought.”
Cataloging this diversity is important for understanding the potential environmental impacts of human activities such as building and mining.
“If you don’t know what you’re looking at, you can’t judge anything about its range or rarity,” says Crews.
Many mesothelial spiders are found in very small geographical areas, probably due to their aversion to travel and their burrow-dwelling lifestyle. These narrow ranges are the trapdoor spiders of Batu Caves (rifistius batuensis) from Malaysia and known only from a handful of limestone caves, it is particularly endangered.
But there is more to spider life to discover. According to Crews, new species of spiders are described every day, and in 2020 he added 977 species to the list known by scientists.
“There are currently 50,979 active species. Spiders are among the most diverse land arthropods,” she says.
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