Outcrops extend on to two offshore islands: Tarutao Island on the Thai side of the border, and Langkawi Island on the Malaysian side.Earlier studies by Kobayashi and his colleagues (summarised in Kobayashi and Hamada, 1984) tended to be descriptions of .spot faunas. small collections of a few inver- tebrate fossils published as separate notes. and their mutual relationships are not obvious.