Marine invertebrate fossils from the Permian–Triassic boundary beds of two core sections in the northern Perth Basin, Western Australia

Marine macroinvertebrate fossils from two petroleum exploration cores, Apium-1 and Redback-2, are described, and found to contain two separate assemblages. The assemblage from the Apium-1 core was recovered from an ca 5-m-thick interval (2756.35–2751.28 m) in the basal Hovea Member (‘inertinitic interval’) of the Kockatea Shale and includes the following forms: ?Spinomarginifera sp., Cimmeriella sp., ?Etherilosia sp., Elivina sp., Cleiothyridina sp., and Paeckelmanelloidea gen. et. sp. indet. (all brachiopods). The age of this assemblage is interpreted as Changhsingian, as constrained by its association with the palynofloral Dulhuntyispora parvithola Zone. The assemblage from the Redback-2 core was recovered from the ‘sapropelic interval’ of the Hovea Member of the Kockatea Shale between 3806 m and 3786 m and comprises the following forms: Lingulidae gen. et sp. indet. (brachiopod), Claraia perthensis Dickins & McTavish, Crittendenia cf. australasiatica (Krumbeck), ?Paralledon sp. (bivalves), ?Otoceras sp. (ammonoid), Microconchus utahensis Zatoń, Taylor & Vinn (microconchid) and Magniestheria mangaliensis (Jones) (spinicaudatan). Among these, the first local appearances of the lingulid species, ?Otoceras sp. and M. mangaliensis are associated with the palynofloral Protohaploxypinus microcorpus Zone and are interpreted as latest Changhsingian in age. Other occurrences of the Redback-2 fossil assemblage overlap with the palynofloral Kraeuselisporites saeptatus Zone and are considered to be of earliest Triassic (Griesbachian) age. G.R. Shi [[e-mail]] and Sangmin Lee [[e-mail]], School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia; Ian Metcalfe [[e-mail]], Earth Sciences, Earth Studies Building C02, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia; Daoliang Chu [[e-mail]], State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China; Huiting Wu [[e-mail]], College of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing, PR China; Tinglu Yang [[e-mail]], Faculty of Geosciences, East China University of Technology, Nanchang 330013, PR China; Yuri D. Zakharov [[e-mail]], Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, 690022 Russia.

本文描述了两口石油勘探岩心（Apium-1与Redback-2）中的海洋大型无脊椎动物化石（marine macroinvertebrate fossils），发现其包含两套独立的化石组合（assemblages）。Apium-1岩心的化石组合采自科卡蒂页岩（Kockatea Shale）底部霍维亚段（Hovea Member，‘惰性质层段’）约5米厚的层位（2756.35–2751.28 m），包含以下类群：？Spinomarginifera未定种（?Spinomarginifera sp.）、Cimmeriella未定种（Cimmeriella sp.）、？Etherilosia未定种（?Etherilosia sp.）、Elivina未定种（Elivina sp.）、Cleiothyridina未定种（Cleiothyridina sp.）以及Paeckelmanelloidea属种未定（Paeckelmanelloidea gen. et sp. indet.，均为腕足类（brachiopods））。该组合的时代被解释为长兴阶（Changhsingian），其限定依据是与孢粉相（palynofloral）Dulhuntyispora parvithola带（Dulhuntyispora parvithola Zone）伴生。Redback-2岩心的化石组合采自科卡蒂页岩霍维亚段的‘腐泥质层段’（sapropelic interval），层位为3806 m至3786 m，包含以下类群：Lingulidae属种未定（Lingulidae gen. et sp. indet.，腕足类（brachiopod））、Claraia perthensis Dickins & McTavish、Crittendenia cf. australasiatica (Krumbeck)、？Paralledon未定种（?Paralledon sp.，双壳类（bivalves））、？Otoceras未定种（?Otoceras sp.，菊石类（ammonoid））、Microconchus utahensis Zatoń, Taylor & Vinn（微壳虫类（microconchid））以及Magniestheria mangaliensis (Jones)（介甲类（spinicaudatan））。其中，Lingulidae类群、？Otoceras未定种以及M. mangaliensis的首次本地出现与孢粉相Protohaploxypinus microcorpus带（Protohaploxypinus microcorpus Zone）伴生，时代被判定为晚长兴期。Redback-2化石组合的其他产出层位与孢粉相Kraeuselisporites saeptatus带（Kraeuselisporites saeptatus Zone）重叠，时代被认定为早三叠世（earliest Triassic）早期（格里斯巴赫阶（Griesbachian））。作者及单位：G.R. Shi（邮箱：[e-mail]）与Sangmin Lee（邮箱：[e-mail]），伍伦贡大学地球、大气与生命科学学院，澳大利亚新南威尔士州伍伦贡市北菲尔德大道，邮编2522；Ian Metcalfe（邮箱：[e-mail]），新英格兰大学环境与乡村科学学院地球科学系地球研究大楼C02，澳大利亚新南威尔士州阿米代尔，邮编2351；褚道良（Daoliang Chu，邮箱：[e-mail]），中国地质大学（武汉）地球科学学院生物地质与环境地质国家重点实验室，中国武汉430074；吴慧婷（Huiting Wu，邮箱：[e-mail]），中国矿业大学（北京）地球科学与测绘工程学院，中国北京；杨廷禄（Tinglu Yang，邮箱：[e-mail]），东华理工大学地球科学学院，中国南昌330013；Yuri D. Zakharov（邮箱：[e-mail]），俄罗斯科学院远东分院远东地质研究所，俄罗斯符拉迪沃斯托克690022。