Komaspis

Abstract: Agnostus (Ptychagnostus?) orientalis Kobayashi, 1935 from the Olenoides Zone of the Machari Formation of South Korea, is a species of Agnostotes (Pseudoglyptagnostus) Lu, 1964, which is an agnostoid trilobite of medial Late Cambrian age rather than early Middle Cambrian. Kobayashi used the Olenoides to denominate a mixed zone of trilobites of Middle and Late Cambrian ages, and his 5 biozonations for the Machari Formation are incorrect. The occurrence of Coreolenus, Cheiruroides, Oryctocephalus, Pagetia , Tonkinella, Glyptagnostus, Pseudoglyptagnostus and Hedinaspis of Early to Late Cambrian age in Chunghwa, North Korea and in Neietsu and Bunkei, South Korea, shows the presence of a slope biofacies, which should be affiliated with the North China Platform, as the side facing the Pacific Ocean. This slope biofacies in Korea, was the northeast extension of the Chiangnan Belt of South China, where a continuous belt of slope biofacies with southwest northeast direction, existed from North Vietnam, via southwest Guangxi, eastern Guizhou, western Hunan, northern Jiangxi, southern Anhui, western Zhejiang, southern Jiangsu (including Shanghai) to Korea. This belt is continuous without any serious geographical displacement. It clearly shows that the North China (or Sino Korean) and Yangtze Platforms, or “Blocks” of some authors, have kept their northern and southern geographical positions as shown on the present geographical map, they probably belonged to one larger platformal area, and there is no separation of the North and South China Blocks during the Cambrian, as many authors have indicated in different reconstruction maps for Cambrian paleogeography (e.g.,Lin, Fuller and Zhang, 1985; Zhao and Robert, 1987). Agnostus (Ptychagnostus?) orientalis Kobayashi and its associated species of Irvingella and Pseudagnostus , are redescribed and refigured. Komaspis Kobayashi, 1935 may be a junior synonym of Irvingella Ulrich and Resser, in Walcott, 1924. Komaspis and Eochuangia are of Late Cambrian Changshanian age rather than Middle Cambrian as suggested by Kobayashi in 1935. \;: Agnostus (Ptychagnostus?) orientalis Kobayashi, 1935 from the Olenoides Zone of the Machari Formation of South Korea, is a species of Agnostotes (Pseudoglyptagnostus) Lu, 1964, which is an agnostoid trilobite of medial Late Cambrian age rather than early Middle Cambrian. Kobayashi used the Olenoides to denominate a mixed zone of trilobites of Middle and Late Cambrian ages, and his 5 biozonations for the Machari Formation are incorrect. The occurrence of Coreolenus, Cheiruroides, Oryctocephalus, Pagetia , Tonkinella, Glyptagnostus, Pseudoglyptagnostus and Hedinaspis of Early to Late Cambrian age in Chunghwa, North Korea and in Neietsu and Bunkei, South Korea, shows the presence of a slope biofacies, which should be affiliated with the North China Platform, as the side facing the Pacific Ocean. This slope biofacies in Korea, was the northeast extension of the Chiangnan Belt of South China, where a continuous belt of slope biofacies with southwest northeast direction, existed from North Vietnam, via southwest Guangxi, eastern Guizhou, western Hunan, northern Jiangxi, southern Anhui, western Zhejiang, southern Jiangsu (including Shanghai) to Korea. This belt is continuous without any serious geographical displacement. It clearly shows that the North China (or Sino Korean) and Yangtze Platforms, or “Blocks” of some authors, have kept their northern and southern geographical positions as shown on the present geographical map, they probably belonged to one larger platformal area, and there is no separation of the North and South China Blocks during the Cambrian, as many authors have indicated in different reconstruction maps for Cambrian paleogeography (e.g.,Lin, Fuller and Zhang, 1985; Zhao and Robert, 1987). Agnostus (Ptychagnostus?) orientalis Kobayashi and its associated species of Irvingella and Pseudagnostus , are redescribed and refigured. Komaspis Kobayashi, 1