[关键词]
[摘要]
文中通过对晚二叠世长兴期(Changhsingian)至晚三叠世瑞替期(Rhaetian)全球1 421个化石点采集到的9 934条腕足动物化石数据分成九个期进行统计分析,总结出腕足动物随时空分布变化的基本模式。从腕足动物类群的构成上来看,晚二叠世长兴期长身贝目分子占全球总属数44%,占据绝对的主导地位,其次为占14%的石燕目,另外7目均不超过10%。经过二叠纪末生物大灭绝事件,长身贝目、直形贝目和正形贝目到早三叠世蒂纳尔亚期(Dienerian)完全消失,而小嘴贝目、准石燕目、穿孔贝目和无窗贝目在早三叠世奥伦尼克期(Olenekian)之后开始逐渐恢复,共同成为三叠纪中后期腕足动物的主要组成分子。从纬度分布上来看,晚二叠世长兴期,腕足动物主要分布于北纬40°到南纬80°之间,而科级分异度最高的区域则主要位于北纬0—40°和南纬3°—60°;二叠纪末大灭绝事件后,早三叠世格里斯巴赫亚期(Griesbachian)的腕足动物残存于北纬0—40°和南纬50°—60°区间内,到蒂纳尔亚期仅在北纬0—40°范围内有极少量腕足动物记录,奥伦尼克期腕足动物开始恢复也是从北纬0—40°和南纬50°—60°逐渐向两侧扩大,到晚三叠世几乎遍布全球。
[Key word]
[Abstract]
Based on the statistic analysis of 9 934 brachiopod fossil occurrences collected from 1 421 fossil sites all over the world from Changhsingian(Late Permian)to Rhaetian(Late Triassic),the basic diversity and spatial and temporal patterns of brachiopods are studied in this paper.From the composition of the brachiopods from Changhsingian,Productida accounted for 44% of the total genus number,and occupied an absolutely dominant position.The remaining eight orders,in addition to Spiriferida which accounted for 14%,are no more than 10%.Effected by the endPermian mass extinction,the orders Productida,Orthotetida and Orthida completely disappeared after the Dienerian of Early Triassic,only the orders Rhynchonellida,Spiriferinida and Lingulida continued in the Triassic.After the Olenekian(Early Triassic),Rhynchonellida,Spiriferinida,Terebratulida and Athyridida survived and began to recover gradually and became the main groups of the Late Triassic brachiopods.Statistic data of palaeolatitude distribution of brachiopods show that the Changhsingian brachiopods were mainly distributed between 40°north latitude to 80°south latitude,while the most prominent zones were respectively located in the 0—40°north latitude and 30°—60°south latitude.After the end-Permian mass extinction,the Early Triassic brachiopods survived in the latitude zones between 0—40°north and 50°—60°south during the Dienerian,only very small amount of brachiopods survived in the zone between 0—40°north,where brachiopods began to recover in the Olenekian and gradually expanded globally in the Middle and Late Triassic.
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[基金项目]
国家自然科学基金(41290260,41273081,41202004);中国科学院战略性先导科技专项(B 类)(XDB18000000)联合资助