Furongian (late Cambrian) trilobites from the Asioptychaspis subglobosa Zone of the Hwajeol Formation, Korea

Park, T.-Y.S. & Kihm, J.-H., 3.10.2014. Furongian (late Cambrian) trilobites from the Asioptychaspis subglobosa Zone of the Hwajeol Formation, Korea. Alcheringa 39, xxx-xxx. ISSN 0311-5518 The Hwajeol Formation of the Taebaek Group, Korea extends from the Jiangshanian Stage to Cambrian Stage 10. The lower part of the formation incorporates the Asioptychaspis Zone, which is closely correlated to the Asioptychaspis-Tsinania Zone of North China. This study documents silicified trilobites from the lower part of the Hwajeol Formation in the Sagundari section. Asioptychaspis subglobosa occurs throughout the interval; hence the biozone is renamed as the Asioptychaspis subglobosa Zone in this study. The Asioptychaspis subglobosa Zone of the Hwajeol Formation yields 14 polymerid species belonging to 14 genera. Of these, 11 species including three new species are documented for the first time in Korea. Among other taxa, the occurrence of Caznaia is stratigraphically significant because two biozones were established in Australia based on representatives of this genus: i.e., the Rhaptagnostus clarki patulus-Caznaia squamosa-Hapsidocare lilyensis and Rhaptagnostus clarki prolatus-Caznaia sectatrix zones in ascending order. Owing to the lack of cosmopolitan trilobites, the international correlation of these Iverian biozones has been equivocal. The occurrence of Caznaia from the Asioptychaspis subglobosa Zone of Korea indicates that the Rhaptagnostus clarki patulus-Caznaia squamosa-Hapsidocare lilyensis and Rhaptagnostus clarki prolatus-Caznaia sectatrix zones of Australia are correlated with the Asioptychaspis subglobosa Zone of Korea and the Asioptychaspis-Tsinania Zone of North China. Tae-Yoon S. Park [typark@kopri.re.kr] and Ji-Hoon Kihm [jhkihm@kopri.re.kr] (corresponding author), Division of Polar Earth-System Sciences, Korea Polar Research Institute, Incheon 406-840, Korea.