Pliocene corals from the Togopi Formation of the Dent Peninsula, Sabah, northeastern Borneo, Malaysia

Abstract

Saw, J.V.M., Hunter, A.W., Johnson, K.G. & Abdul Rahman, A.H.B., November 2018. Pliocene corals from the Togopi Formation of the Dent Peninsula, Sabah, northeastern Borneo, Malaysia. Alcheringa 43, 291–319. ISSN 0311-5518

The palaeobiology of the Malay Archipelago region remains poorly documented, despite its present-day significance as a modern global marine biodiversity hotspot. The Togopi Formation of the Dent Peninsula, situated in Borneo on the western Sulu Sea and eastern coast of Sabah, Malaysia, preserves Plio-Pleistocene sedimentary sequences interpreted to represent localized transgressive episodes, and which have a relatively high coral diversity. Fossil corals were sampled from three available quarries on the Dent Peninsula, the sediments of which have been previously dated as 4.5–3.4 Ma in age based on foraminiferal data and radiometric analyses. These Pliocene corals are identified here based on their macromorphology, micromorphology and microstructural characteristics. In total, this study describes 28 fossil coral taxa, with 16 genera recognized and 22 taxa identified to species level, 21 of which can be confidently assigned to extant species. These new data have resulted in revised stratigraphic ranges for eight of these species. As the most comprehensive systematic survey of corals from the Pliocene of the Indo-Pacific to date, this study indicates a high diversity of corals on the margin of the Sabah Sea, Borneo, at this time, including taxa found today, thus casting doubt on the local impact of the Plio-Pleistocene extinction previously reported from faunal analyses of the central Indo-Pacific.

Jasmin V.M. Saw [[email protected]] Department of Petroleum Geosciences, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; Aaron W. Hunter* [[email protected]] Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK; Kenneth G. Johnson [[email protected]] Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; Abdul Hadi B Abdul Rahman [[email protected]] Department of Petroleum Geosciences, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia. *Also affiliated with: School of Earth Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.

Key words:

• Cnidaria
• Anthozoa
• Scleractinia
• Biodiversity
• Coral Triangle
• Malaysian Borneo

Acknowledgements

We thank the management of Felda Wilayah palm-oil plantation for allowing access into the quarries within their plantation. This research was funded by Universiti Teknologi PETRONAS-University Research Internal Fund (UTP-URIF) and Yayasan-Universiti Teknologi PETRONAS (Y-UTP) grants. We acknowledge Viola Warter (Royal Holloway, University of London) for the Tridacna sp. indet. dating analysis, for which she performed the sample preparation, clean-room wet geochemistry and TIMS analysis. We also thank Prof. Matthew Thirlwall and Dr Christina Manning for help in the TIMS analysis. Dr Willem Renema (Naturalis Biodiversity Centre, Leiden, Netherlands) is thanked for providing age constraints for the sites through collaboration with Viola Warter. JSVM would like to thank The Paleontological Society for awarding her the Rodney M. Feldmann Student Research Award to fund fieldwork, Mr Tan Siong Kiat [curator of the Lee Kong Chian Natural History Museum (formally Raffles Museum) of the National University of Singapore] and Jill Darrell (Natural History Museum, London) for collection access, and Nadia Santodomingo (Natural History Museum, London) for her guidance on coral taxonomy.