Tae-Yoon S. Park
1 Division of Polar-Earth System Sciences, Korea Polar Research Institute, Incheon 406-840, KoreaJi-Hoon Kihm
1 Division of Polar-Earth System Sciences, Korea Polar Research Institute, Incheon 406-840, KoreaJusun Woo
1 Division of Polar-Earth System Sciences, Korea Polar Research Institute, Incheon 406-840, KoreaYong-Yi Zhen
2 Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947-953 Londonderry Rd., Londonderry, NSW 2753, AustraliaMichael Engelbretsen
3 Research Affiliate, Biological Sciences, Macquarie University, NSW 2109, AustraliaJongsun Hong
4.Department of Earth and Environmental Sciences, Korea University, 136-713, KoreaSuk-Joo Choh
4.Department of Earth and Environmental Sciences, Korea University, 136-713, KoreaDong-Jin Lee
5 Department of Earth and Environmental Sciences, Andong National University, Andong 760-749, KoreaThis research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (#PN15090, KOPRI). Copyright permissions for re-illustrating the images of Lipopora and Cambroctoconus kyrgyzstanicus from the journals Alcheringa and Bulletin of Geosciences are greatly acknowledged. DJL was supported by a grant from the National Research Foundation of Korea (NRF 2012-005612). Dr Susan Turner, Brisbane, is thanked for her careful editing and linguistic assistance. This study is a contribution to IGCP Project 591: The Early to Middle Paleozoic Revolution.
Five species, Lipopora lissa Jell and Jell, 1976, Lipopora daseia Jell and Jell, 1976, Tretocylichne perplexa Engelbretsen, 1993 from Australia, Cambroctoconus orientalis Park, Woo, Lee, Lee, Lee, Han and Chough, 2011 from China, and Cambroctoconus kyrgyzstanicus Peel, 2014 from Kyrgyzstan, belonging to the Cambrian stem-group cnidarians have been documented in the fossil record. Cambroctoconus coreaensis sp. nov., interpreted here as a stem-group cnidarian, from the Seokgaejae section in the Daegi Formation, Taebaek Group (Cambrian Series 3), Taebaeksan Basin, central-eastern Korean Peninsula, has a slender cup-shaped skeleton. A cladistic analysis produced 21 most parsimonious trees, which invariably placed the six stem-group cnidarians below the crown-group, but their relationships within the stem-group are unresolved. Nine out of the 21 trees suggest a monophyletic relationship for the Cambrian stem-group cnidarians, whereas in six other trees a monophyly of Cambroctoconus and Tretocylichne appeared as the sister-group to the crown-group cnidarians with Lipopora at the most basal branch. This result may reflect the fact that crown-group cnidarians evolved in the Precambrian, and suggests that the diversity of stem-group cnidarians was a result of an independent radiation in the Cambrian.
Tae-Yoon S. Park, Ji-Hoon Kihm, Jusun Woo, Yong-Yi Zhen, Michael Engelbretsen, Jongsun Hong, Suk-Joo Choh, Dong-Jin Lee.2016. Cambrian Stem-group Cnidarians with a New Species from the Cambrian Series 3 of the Taebaeksan Basin, Korea[J]. Acta Geologica Sinica(),90(3):827-837
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