Biostratigraphy, Taxonomy, and Paleogeography of Conodont Sequences in the Middle and Late Devonian (Frasnian) Tropics

中、晚泥盆世（弗拉斯尼世）热带地区牙形刺序列的生物地层学、分类学和古地理

• 批准号: 8706567
• 负责人: Gilbert Klapper
• 金额: $ 9.48万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-06-01 至 1989-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8706567&HistoricalAwards=false
• 关键词: Biostratigraphy; Taxonomy; Paleogeography; Conodont; Sequences

Frasnian conodont sequences in the Montagne Noire and Alberta are superbly developed in their biostratigraphic continuity and excellent preservation of faunas representative of the Palmatolepis biofacies. Through graphic correlation, the sequence composited from these two areas will become a standard of reference for this biofacies, characteristic of outer shelf to basinal sequences throughout the inferred Devonian tropics. There has been great inconsistency in published identifications of species of Palmatolepis and Ancyrognathus resulting in erroneous understanding of ranges of the two principal groups on which the Frasnian "standard" zonation is based. Furthermore, there has been little study of the Polygnathus biofacies, characteristic of inner shelf Frasnian sequences. My research based on multielement taxonomy and shape analysis of platform elements has drastically revised discrimination of species of Palmatolepis and Ancyrognathus and consequently their stratigraphic ranges. The result is a near doubling in number of zones within the Palmatolepis biofacies, but their resolution is far exceeded by that obtainable through graphic correlation. Correlation between the Palmatolepis and Polygnathus biofacies remains difficult, but is probably resolvable through graphic methods. Proposed research will rigorously test these new biostratigraphic and taxonomic results in widely scattered localities throughout the Devonian tropics, with the additional long-range purpose of developing a comprehensive analysis of Frasnian conodont paleogeography.

黑山和艾伯塔省的弗拉斯尼亚牙形刺序列在其生物地层连续性和代表棕榈石生物相的动物群方面得到了极好的保存。 通过图形关联，这两个区域合成的序列将成为该生物相的参考标准，该生物相是整个推断的泥盆纪热带地区外陆架到盆地序列的特征。 已发表的掌鳞属和长颌属物种鉴定存在很大的不一致，导致对弗拉斯尼亚“标准”分区所依据的两个主要类群的范围的错误理解。 此外，对内陆架弗拉斯尼亚序列特征的多颌生物相的研究很少。 我的研究基于多元素分类学和平台元素的形状分析，极大地修正了掌鳞鱼和长颌龙物种的区分，从而改变了它们的地层范围。 结果是掌鳞生物相内的区域数量几乎增加了一倍，但其分辨率远远超过通过图形关联获得的分辨率。 掌鳞鱼和多颌生物相之间的关联仍然很困难，但可能可以通过图形方法来解决。 拟议的研究将在整个泥盆纪热带地区广泛分布的地区严格测试这些新的生物地层学和分类学结果，其长期目的是对弗拉斯尼亚牙形刺古地理进行全面分析。