Trilobites of Thailand’s Cambrian-Ordovician Tarutao Group

Tuff-bearing upper Cambrian–lowermost Ordovician strata on Ko Tarutao (Tarutao Island) in Satun province, southernmost peninsular Thailand, contain a rich trilobite fauna relevant to global biostratigraphy, peri-Gondwanan palaeogeography, and shifting evolutionary mode. This area of Sibumasu, a lower Palaeozoic marginal Gondwanan terrane, is shown to be closely associated with Australia, North China (Sino-Korea), and other continental fragments from the supercontinent’s northern equatorial sector including South China. Shared fauna with Kazakhstan are also notable and shared similiarities with Laurentia are of similar magnitude to those of some other parts of equatorial Gondwana. Extensive collections from eight different sections have yielded a number of newly-discovered taxa. With the new taxa and revision of taxa known previously, we refine the age of the upper formations of the Tarutao Group as the middle of Cambrian Stage 10 and lower Tremadocian. Newly described taxa include Tsina...