EN
Thalassaphorura is reported for the first time in Northwest China. Four members of the genus were recorded, including three new species (T. qinlingensis sp. nov., T. bisetosa sp. nov., T. petiti sp. nov.) and one known species (T. pornorskii Sun, Chen et Deharveng, 2010). All-three new species possess modified chaetae (male ventral organ) on ventral tube - a character rarely present in congeners. Apart from this, T. bisetosa sp. nov. is characterized by an unique feature - only two small dental chaetae on the furcal area, which differentiates it from all other known Thalassaphorura.