Middle Permian (Guadalupian) Fusulines from the Xilanta Formation in the Gyanyima area of Burang County, southwestern Tibet, China

This paper reports a diversified fusuline fauna from the Middle Permian (Guadalupian) Xilanta Formation in the Gyanyima area, Burang County, southwestern Tibet, China. Nine genera, Lantschichites, Kahlerina, Nankinella, Yangchienia, Chusenella, Verbeekina, Armenina, Paraverbeekina and Neoschwagerina are recognized.Anew species Yangchienia gyanyimaensis n. sp. is established. This fauna indicates a Midian age in terms of the coexistence of Kahlerina, Lantschichites and Neoschwagerina. Paleobiogeographically, the fauna closely resembles that from the Lasaila exotic limestone block of Tibet, both resemble the fusuline assemblages known from the western Cimmerian continents in the Western Tethys Province. However, the absence of Afghanella and Sumatrina in the fauna suggests that the Gyanyima limestone block as well as the Lasaila exotic limestone block, the Batain plain of Oman and the Salt Range of Pakistan, were affected by relatively cool water during the Middle Permian.