Researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and their collaborators from Australia have quantitatively studied Silurian (Telychian) conodont distribution in the Yangtze Platform in South China. 

Related results were published in Journal of Asian Earth Sciences. 

Conodonts are important for global biostratigraphic correlation of strata containing Palaeozoic and Triassic marine faunas. Previous studies demonstrated that Telychian conodont distributions were related to the associated palaeoenvironments. 

Diverse Telychian (Llandovery Series, Silurian System) conodont faunas have been documented from the South China Palaeoplate. The researchers investigated the spatial distribution of the Telychian conodont associations based on data from six selected sections in the Yangtze Platform.

Statistical analysis showed that two Telychian conodont biofacies could be observed in South China: the Dapsilodus-Decoriconus Biofacies which is restricted to deep-water environments, and the Apsidognathus-Galerodus Biofacies which is indicative of shallower water environments. 

One regression and two transgressions are deduced from relative abundance patterns of characteristic conodont taxa comprising these biofacies.

Vertical changes of conodont biofacies in the Baizitian and Xuanhe sections permit the recognition of transgressive-regressive patterns that are closely similar to published sea-level curves for the Early Silurian. Therefore, vertical variations in abundance of specific Silurian conodont taxa can be used as proxies for inferring major changes in sea-level. 

This research was supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences.