The Anisian (Middle Triassic) brachiopods from the southern Qilian Mountains, north-western China

The Anisian (Middle Triassic) witnessed the diversification of brachiopods after the Permian/Triassic (P/Tr) extinction. The Anisian brachiopod fauna from the southern Qilian Mountains in north-western China has the highest taxonomic diversity at the species level among coeval faunas worldwide. Nevertheless, many taxa from this remote region remain poorly defined and therefore require emendation. Here we describe 23 species (including two uncertain species) in 15 brachiopod genera based on well-preserved carbonate and silicified specimens collected from the Anisian Dajialian and Qieermagou formations in Tianjun, southern Qilian Mountains. Two new genera (Crenulatomargus, Tianjunospina) and six new species (Costirhynchopsis xui, Crenulatomargus terebratuliformis, Schwagerispira elegans, Lepismatina? inusitata, Tianjunospina junheensis, Qilianoconcha circularis) are erected. The diagnoses of Triasorhynchia, Yangkongia, Sinucostella, Aequspiriferina, Qilianoconcha, and Parantiptychia are e...安尼期（Anisian，中三叠世）见证了二叠纪/三叠纪（P/Tr）大灭绝后腕足动物（brachiopods）的辐射演化。产自中国西北祁连山（Qilian Mountains）南部的安尼期腕足动物群，在全球同期动物群中拥有最高的物种级分类多样性（taxonomic diversity）。然而，该偏远区域的诸多类群目前仍界定模糊，亟需开展修订工作。本文基于采自祁连山南部天峻地区安尼阶大架山组与切尔玛沟组中保存完好的碳酸盐岩（carbonate）及硅化标本（silicified specimens），记述了15个腕足动物属下的23个物种（含2个未定种）。文中建立2个新属（Crenulatomargus、Tianjunospina）以及6个新种：Costirhynchopsis xui、Crenulatomargus terebratuliformis、Schwagerispira elegans、Lepismatina? inusitata、Tianjunospina junheensis、Qilianoconcha circularis。并对Triasorhynchia、Yangkongia、Sinucostella、Aequspiriferina、Qilianoconcha及Parantiptychia的鉴别特征进行了修订。