Late Miocene teleost fish otoliths from Brunei Darussalam (Borneo) and their implications for palaeoecology and palaeoenvironmental conditions

Abstract

ABSTRACT We report here diverse Late Miocene fish assemblages based on otoliths collected from sedimentary rocks deposited in coastal marine settings in northern Borneo (Seria and Miri formations and Tutong beach). Surface-collected, large-sized otoliths, representing > 96% of the whole assemblage, are dominated by the families Sciaenidae and Ariidae, while Haemulidae, Engraulidae, and Lactaridae can be common at certain sites. Additional taxa were revealed by screen-washing of the sediments from selected sites including taxa from the families of Congridae, Bregmacerotidae, Apogonidae, Gobidae, Sillaginidae, and Cepolidae. Among the sciaenids, we describe six new taxa (Advenasciaena bruneiana, Atrobucca borneensis, Bruneisciaena schwarzhansi, Nibea ambugensis, Nibea stintoni, and Protonibea nolfi), and we also report the first fossil occurrence of some other groups (e.g. Lactarius lactarius, Acanthocepola sp.) from the Indo-Australian Archipelago (IAA). All these discoveries add to our understanding of fish palaeobiodiversity in the IAA where today’s highest marine biodiversity exists. The compositions of the faunas reflect a shallow marine coastal palaeoenvironment with close connection to estuaries where some of the reported fishes might have migrated seasonally or daily with the tide. Turbid, suspension-loaded water might be also presumed, where ariids, sciaenids, and the haemulid Pomadasys are often observed today. ZooBank LSID for the described genera: Advenasciaena zoobank.org:act:5D6D3223-462F-4488-88BE-8DDDB107BFB6 Bruneisciaena urn:lsid:zoobank.org:act: 090DAD2F-FB18-43CB-9CA9-5F9FE224CA54 ZooBank LSID for the described species: Advenasciaena bruneiana urn:lsid:zoobank.org:act: D14930B9-5847-4A1F-9D20-EFC0501F3B3D Atrobucca borneensis urn:lsid:zoobank.org:act: 36E0F8EC-0266-4BBB-B00A-B43C1B1C7557 Bruneisciaena schwarzhansi urn:lsid:zoobank.org:act: B9B2F637-CC09-44A3-AEE6-6C8EE76FBE34 Nibea ambugensis urn:lsid:zoobank.org:act: 8C780272-A910-404D-89FA-C0BB110B9CEF Nibea stintoni urn:lsid:zoobank.org:act: 8D750E35-8BD4-481A-822D-7F4DA3816E04 Protonibea nolfi urn:lsid:zoobank.org:act: 81BC0700-50E1-400B-9034-F83DDA6C7710