Cave Stedocys spitting spiders illuminate the history of the Himalayas and Southeast Asia

Stedocys spitting spiders (Araneae: Scytodidae) inhabit subterranean environments and have poor dispersal abilities. The Cenozoic Indian–Eurasian collision affected the regional biota of this genus, which occurs in parts of Indochina. Phylogeographical pattern of Stedocys based on multigene DNA sequence datasets reveals how tectonic history drove four biological splits. The first split dates to the late Paleocene–Eocene and involves the Truong Son Mountain Range and Mekong River. The other splits associate with the Eocene–Oligocene transition, including the Tonkin (Beibu) Gulf, the Ma River, and the Red River. These events indicate four early uplifts of the Himalayas and Tibetan Plateau. Our results cannot reject the hypothesis that uplifting of the Himalayas and Tibetan Plateau region due to crustal thickening and the lateral extrusion of Indochina occurred synchronously during the Paleocene–Oligocene transition in reaction to the Indian–Eurasian collision. Species of Stedocys cluster ...