First documentation of early Silurian conodonts from western Thailand and its geological implications

The early Silurian conodonts are firstly described and illustrated from western Thailand. Samples were collected from the Kroeng Kravia Forest Park area for conodont and lithofacies analyses. An upper Telychian Lower Pterospathodus amorphognathoides amorphognathoides Subzone is recognized for the studied succession. Three lithofacies were identified from the carbonate succession, including stromatolite–thrombolite limestone, nodular limestone, and red limestone. Both analyses on lithofacies and conodont assemblages indicate a deeper marine depositional environment. The conodont fauna in the study area is similar to that from Baoshan of Yunnan Province and Langao of Shaanxi Province in West China and resembles that from similar depositional environments in Australia, Laurentia, and peri-Gondwana, suggesting good connections among these regions by ocean currents. • The first Silurian conodonts from western Thailand in the Sibumasu Terrane are described and belong to the upper Telychian Lower Pterospathodus amorphognathoides amorphognathoides Subzone. • Three limestone lithofacies are recognized, the stromatolite-thrombolite, nodular, and red limestones indicate a deeper marine environment. • The conodont fauna is similar to that from the Baoshan and Langao areas of China and resembles that from the similar depositional environments in Australia, Laurentia, and peri-Gondwana, suggesting good connections between these regions by ocean currents.