Establishment of paleobiogeography and historical change of distribution based on radiolarian fossils

基于放射虫化石的古生物地理学的建立及其分布的历史变迁

基本信息

批准号：
10836004
负责人：
AITA Yoshiaki
金额：
$ 1.34万
依托单位：
Utsunomiya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10836004/
关键词：
Radiolaria Early & Middle Triassic Middle & Late Jurassic database all morphotypes New Zealand high latitude paleobiogeography ジュラ紀中期三畳紀中期ムリヒクテレーンテーチス地域三畳紀

项目摘要

All the morphotypes of the radiolarian assemblages from the Early and Middle Triassic and Middle and Late Jurassic time in high and low latitudes have been digitized and established as a paleontological database. These faunas from southern high latitudes are from the Middle Triassic (Anisian-Ladinian) siliceous shale and phosphatic concretions taken from the Waipapa Terrane, North Island, and from phosphatic concretions at Bull Creek, Caples Terrane, South Island, New Zealand. The Middle Jurassic (Toarcian-Aalenian) radiolarian faunas taken from the Ururoa Formation, Kawhia Coast were also addied to the paleontological database. More than 300 radiolarian morphotypes of the Buchenstein Limestone faunas which is representative of low latitude during the Middle Triassic (Ladinian), have been dizitized in order to compare with age-equivalent faunas. Biostratigraphy of the Early and Middle Triassic bedded chert sequences from the Minowa section, Ashio terrane has been carried out. Almost 150 outcrop photos (1mX1m in size) were taken from the continuous Early Triassic siliceous shale succession, Karasawa-san and were dizitized for the detailed geologic study.Well-preserved Middle Triassic (Ladinian) radiolarian faunas have been documented from phosphatic nodules collected from the Waipapa Terrane, New Zealand and the Omolon Massif, northeastern Siberia, respectively. Both New Zealand and northeastern Siberia faunas include many species that are well-known from European Tethys area as well as abundant non-Tethyan radiolarians that are characteristic of these faunas. Distinctive pylomate spumellarians were described as a new genus Glomeropyle Aita & Bragin together with seven new species. They are only known from northern and southern high latitudes and they are endemic Triassic Radiolaria with a bipolar distribution pattern.

高低纬地区早、中三叠世和中、晚侏罗世放射虫组合形态类型均已数字化，建立了古生物数据库。这些来自南部高纬度地区的动物群来自中三叠世（安尼阶-拉丁阶）硅质页岩和取自北岛怀帕帕地体的磷酸结核，以及新西兰南岛卡普尔斯地体 Bull Creek 的磷酸结核。取自 Kawhia 海岸 Ururoa 地层的中侏罗世（Toarcian-Aalenian）放射虫动物群也被添加到古生物学数据库中。布肯斯坦石灰岩动物群的 300 多种放射虫形态类型是中三叠世（拉丁纪）低纬度的代表，已被数字化，以便与年龄相当的动物群进行比较。对足尾地体 Minowa 剖面的早三叠世和中三叠世层状燧石序列进行了生物地层学研究。近 150 张露头照片（大小 1mX1m）是从连续的早三叠世硅质页岩序列 Karasawa-san 拍摄的，并进行了详细的地质研究。从收集的磷酸结核中记录了保存完好的中三叠世（拉丁阶）放射虫动物群分别是新西兰的怀帕帕地块和西伯利亚东北部的奥莫隆地块。新西兰和西伯利亚东北部的动物群包括欧洲特提斯地区著名的许多物种，以及这些动物群所特有的丰富的非特提斯放射虫。独特的 pylomate spumellarians 被描述为一个新属 Glomeropyle Aita 和 Bragin 以及七个新种。它们仅分布于北部和南部高纬度地区，是三叠纪特有的放射虫，具有两极分布模式。