Triassic radiolarian biostratigraphy of the Semanggol Formation, south Kedah, Peninsular Malaysia

Twenty-seven taxa of the Triassic radiolarian faunas have been identified from seven chert samples collected from an outcrop exposed at a construction site 4.5 km east of Kuala Ketil, south Kedah. The faunas were divided into four assemblage zones: Entactinosphaera chiakensis Zone, late Spathian, Triassocampe coronata Zone, middle Anisian, Triassocampe deweveri Zone, late Anisian and Oertlispongus inaequispinosus Zone, early Ladinian. The radiolarian assemblages indicate an age ranging from late Spathian to early Ladinian, Triassic