Late Palaeozoic corals of Tibet (Xizang) and West Yunnan, Southwest China: successions and palaeobiogeography

A dynamic pattern of coral faunal provincialism in the Carboniferous to Permian sequence is preserved in Tibet–West Yunnan. During the Early Carboniferous, an undifferentiated Eurasian province was present, containing the Kueichouphyllum, Keyserlingophyllum-Siphonophyllia, and Cyathaxonia faunas, that reflect major environmental differences relative to previous interpretations. During the Late Carboniferous–Early Permian, the Indoralian province and the Cathaysian province can be distinguished. The former is recognised by an absence of Late Carboniferous–Asselian corals and by the presence of the Sakmarian–Artinskian Cyathaxonia fauna. The latter contains the Late Carboniferous and Early Permian compound corals Nephelophyllum and Kepingophyllum. As many blocks drifted northward beginning in the late Early Permian, the Indoralian province had evolved into two discrete provinces: the Himalayan and Cimmerian provinces. The Himalayan province as a relic of the Indoralian province was in the northern margin of Gondwanaland. The Cimmerian province between the Himalayan and the Cathaysian provinces consists of the present tectonic blocks: Lhasa, Qiangtang, Tengchong, and Baoshan in Tibet and West Yunnan. It is characterised by Roadian non-dissepimental solitary corals and Wordian–Capitanian compound Waagenophyllidae, as well as some endemic Cimmerian taxa such as Thomasiphyllum and Wentzellophyllum persicum. The Cathaysian province is dominated by Szechuanophyllum and Ipciphyllum. During the Late Permian, the Himalayan province and the Cathaysian province can be recognised. The former contains only small solitary corals, referred to as the Lytvolasma fauna, and the latter is identified by Liangshanophyllum, a fasciculate waagenophyllid.