扬子区奥陶纪和志留纪四射珊瑚的起源、扩散及生物古地理关系

摘 要　 提出扬子区是奥陶纪、志留纪四射珊瑚的起源中心。早古生代扬子区最早出现的四射 珊瑚约有30属?包括穿孔珊瑚类 Calostylis?Yohophyllum?扭心珊瑚类 Briantelasma?Tunguse 提出扬子区是奥陶纪、志留纪四射珊瑚的起源中心。早古生代扬子区最早出现的四射 珊瑚约有30属?包括穿孔珊瑚类 Calostylis?Yohophyllum?扭心珊瑚类 Briantelasma?Tunguse- lasma?包珊瑚类 Amplexoides?Synamplexoides?十字珊瑚类 Eostauria?Ceriaster?Stauria 以及 珊瑚约有30属?包括穿孔珊瑚类 Calostylis?Yohophyllum?扭心珊瑚类 Briantelasma?Tunguse lasma?包珊瑚类 Amplexoides?Synamplexoides?十字珊瑚类 Eostauria?Ceriaster?Stauria 以及 泡沫珊瑚类 Rhizophyllum 等。它们在扬子区中奥陶世和早志留世地层迅速繁衍?尔后扩散至 欧洲、北美和其他地区。扬子区晚奥陶世四射珊瑚群与北欧同期珊瑚有较高的相似性；而该 泡沫珊瑚类 Rhizophyllum 等。它们在扬子区中奥陶世和早志留世地层迅速繁衍?尔后扩散至 欧洲、北美和其他地区。扬子区晚奥陶世四射珊瑚群与北欧同期珊瑚有较高的相似性；而该 区早志留世（包括 Wenlockian 阶）珊瑚群的生物古地理关系与西伯利亚、哈萨克斯坦有紧密联 欧洲、北美和其他地区。扬子区晚奥陶世四射珊瑚群与北欧同期珊瑚有较高的相似性；而该 区早志留世（包括 Wenlockian 阶）珊瑚群的生物古地理关系与西伯利亚、哈萨克斯坦有紧密联 系。扬子区早志留世珊瑚群与澳大利亚东部、北美东部同期珊瑚也有一定的相似性。 区早志留世（包括 Wenlockian 阶）珊瑚群的生物古地理关系与西伯利亚、哈萨克斯坦 系。扬子区早志留世珊瑚群与澳大利亚东部、北美东部同期珊瑚也有一定的相似性。

ORIGIN, DISPERSION AND BIOGEOGRAPHIC AFFINITY OF ORDOVICIAN AND SILURIAN RUGOSE CORALS IN YANGTZE REGION

t is proposed that the Yangtze region may be a center of origin of Ordovician and Silurian rugose corals. The earliest known rugose corals in this region are about 30 genera, including calostylids Calostylis and Yohophyllum, streptelasmatid Briantelasma and Tunguselasma , amplexids Synamplexoides and Amplexoides , stauriids Eostauria, Ceriaster and Stauria, and cystiphylloid Rhizophyllum and Maikottia, etc. The coral fauna developed rapidly from Middle Ordovician to Early Silurian in the Yangtze region, and then dispersed to Europe, North America and other areas. The Late Ordovician rugose corals of the Yangtze region show high similarity to the faunas of North Europe, while the Early Silurian (including Wenlockian) rugose corals from the Yangtze region seem to be close to those of Siberia and Kazakhstan in biogeographic affinity. There are also resemblances among Early Silurian rugose coral faunas of the Yangtze region, eastern Australia, and eastern North America to some extent.