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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.

将高、低纬地区早、中三叠世、中、晚侏罗世放射虫组合的形态类型全部数字化，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(阿尼西亚-拉迪尼期)硅质页岩和磷质结核，来自北岛的Waipapa Terrane，以及新西兰南岛Caples Terrane的Bull Creek的磷质结核。考西亚海岸乌鲁罗亚组中侏罗世(Toarcian-Aalenian)放射虫动物群也被添加到古生物数据库中。为了与年龄相当的动物群进行对比，对代表中三叠世(拉第纪)低纬地区的布痕斯坦石灰岩动物群的300多个放射虫地貌类型进行了年代学研究。对Ashio地体米诺瓦剖面早、中三叠世层状硅质岩序列进行了生物地层学研究。从连续的早三叠世硅质页岩序列Karasawa-San中拍摄了近150张露头照片(大小为1mX1m)，并将其进行了详细的地质研究。分别从新西兰Waipapa地体和西伯利亚东北部奥莫隆地块采集的磷酸盐结核中记录了保存完好的中三叠世(拉迪期)放射虫动物群。新西兰和西伯利亚东北部的动物群都包括许多来自欧洲特提斯地区的著名物种，以及大量的非特提斯放射虫，这是这些动物群的特征。本文记述了一新属，包括7个新种和一个新属。它们仅见于南北高纬度地区，是三叠纪特有的放射虫，呈两极分布格局。