Data from: Latest Carboniferous (late Gzhelian) fusulinids from Timor Leste and their paleobiogeographic affinities

An uppermost Gzhelian bioherm discovered in the central highlands of Timor Leste contains abundant foraminifera belonging to 17 genera. Representatives of the families Biseriamminidae, Biwaellidae, Bradyinidae, Cornuspiridae, Lasiodiscidae, Palaeotextulariidae, Pseudotaxidae, Ozawainellidae, Schubertellidae, Schwagerinidae, Staffellidae and Textrataxidae are present, including 21 species referred to known types and 12 species left in open nomenclature. Two new Schwagerina species are described: Schwagerina timorensis new species, and Schwagerina maubissensis new species. The assemblage belongs to the uppermost Gzhelian Schwagerina robusta–Ultradaixina bosbytauensis Zone although a possible lowest Asselian correlation cannot be excluded (the name Ultradaixina is controversial and sometimes synonymized as Bosbytauella. The case to resolve this issue has been submitted to the Bulletin of Zoological Nomenclature). The bioherm is the oldest carbonate unit so far recorded from the Maubisse Formation and the oldest sedimentary unit biostratigraphically dated in Timor. This discovery has implications for the latest Carboniferous–earliest Permian climate history of Timor that lay in the northern part of the north-south East Gondwana rift system along which the western margin of Australia later developed. The highest peak in fusulinid diversity within the Pennsylvanian–Cisuralian interval and a major marine transgression documented in many regions in Northern Pangaea took place during the latest Gzhelian to earliest Asselian and evidence for this is now extended to southern Pangaea. Cluster analysis, using the Jaccard similarity index at species level, of late Gzhelian fusulinids from 16 regions has been performed. This shows that the Timor fauna is most closely related to faunas from South China and the Changning-Menlian region of Yunnan (China). The assemblages here are distinct from those of three biogeographic regions (Arctic, Uralo-Asian and Irano-Taurids) recognized within the Tropical belt.在东帝汶中部高地发现的最顶部格舍尔阶（Gzhelian）生物礁（bioherm）中，产出了丰富的有孔虫（foraminifera），隶属于17个属。该生物礁包含双砂虫科（Biseriamminidae）、比瓦虫科（Biwaellidae）、布雷迪虫科（Bradyinidae）、旋壳虫科（Cornuspiridae）、扁盘虫科（Lasiodiscidae）、古串珠虫科（Palaeotextulariidae）、假梯管虫科（Pseudotaxidae）、小泽蜓科（Ozawainellidae）、舒伯特蜓科（Schubertellidae）、希瓦格蜓科（Schwagerinidae）、斯塔夫蜓科（Staffellidae）以及织形虫科（Textrataxidae）的代表类群，其中21个物种为已知模式种，另有12个物种采用开放命名法（open nomenclature）进行定名。 本次研究描述了2个希瓦格蜓（Schwagerina）新种：东帝汶希瓦格蜓（Schwagerina timorensis）新种与莫艾西斯希瓦格蜓（Schwagerina maubissensis）新种。该有孔虫组合隶属于最顶部格舍尔阶的粗壮希瓦格蜓—超戴克斯蜓带（Schwagerina robusta–Ultradaixina bosbytauensis Zone），但亦不能排除其与最低阿瑟尔阶（Asselian）存在地层对比的可能性。（注：超戴克斯蜓（Ultradaixina）这一分类名称存在争议，部分学者将其归为博斯比陶蜓（Bosbytauella）的同物异名。目前相关厘定该分类问题的申请已提交至《动物命名学报》（Bulletin of Zoological Nomenclature）。） 该生物礁是目前东帝汶莫艾西斯组（Maubisse Formation）中记录的最古老碳酸盐岩地层单元，同时也是东帝汶经生物地层定年的最古老沉积单元。本次发现对于厘清东帝汶地区晚石炭世至早二叠世的气候历史具有重要意义：东帝汶地处南北向东冈瓦纳裂谷系的北段，该裂谷系后续演化形成了澳大利亚西部陆缘。 宾夕法尼亚亚纪至乌拉尔亚纪（Pennsylvanian–Cisuralian）间隔内纺锤虫（fusulinid）多样性的峰值，以及泛大陆（Pangaea）北部诸多地区记录的大规模海侵事件，均发生于晚格舍尔期至早阿瑟尔期，如今该事件的地质证据已拓展至泛大陆南部地区。研究人员针对16个地区的晚格舍尔期纺锤虫（fusulinid）开展了基于物种级别的雅卡尔相似性指数（Jaccard similarity index）聚类分析，结果显示东帝汶的有孔虫动物群与华南地区及中国云南昌宁-孟连（Changning-Menlian）地区的动物群亲缘关系最近。该组合与热带带内已识别的3个生物地理区——北极区、乌拉尔-亚洲区以及伊朗-陶里达区（Irano-Taurids）——的有孔虫组合均存在显著差异。