COLLABORATIVE RESEARCH: Biotic Diversity and Vertebrate Evolution in Late Devonian Non-Marine Ecosystems of North America

AbstractCollaborative Research：北美晚泥盆世非海洋生态系统中的生物多样性和脊椎动物进化晚泥盆世（3.75 - 3.6亿年）见证了脊椎动物生命的多样化，包括四肢脊椎动物的起源，以及陆地生态系统中植物和无脊椎动物的发展。因此，晚泥盆世脊椎动物和生态系统的描述和分析提供了在这一关键的进化时刻产生新的分类群，新的解剖结构，新的动物群和新的栖息地出现的重要数据的能力。我们之前的工作（1993年至今）在晚泥盆世（法门阶）在宾夕法尼亚州的卡茨基尔组已经产生了保存完好，高度多样化的脊椎动物组合从相同的地层层位的宏化石植物，palynomorphs，节肢动物，和双壳类。在加拿大北极地区晚泥盆世（弗拉斯阶）奥克塞湾群的勘探工作（1999-2000）也揭示了在这个几乎未勘探的区域中重要的含盐单元。本项目将记录和解释北美东部这些晚泥盆世系统的非海洋部分的多样性。时间范围将涵盖晚泥盆世的弗拉斯阶和法门阶，这是演化的一个关键窗口。对法门期卡茨基尔组的野外工作已经迈出了重要的一步;宾夕法尼亚州交通部已经允许从红山地区移除一大块覆盖层，红山是两个早期四足动物分类群和非常多样化的动物群和植物群的来源。在加拿大北极地区弗拉斯期奥克塞湾群的实地考察将集中在现在公认的化石生产力地区。第一个主要目标是恢复，准备和描述晚泥盆世化石材料。对化石组合的系统发育亲缘关系和地层位置的后续调查将允许对生物多样性进行层内和全球比较。层内地层关系的评估将有助于了解河流系统不同部分的生物多样性。这些分析将提供信息：1）有颌类脊椎动物的高级系统发育假说; 2）晚泥盆世四足动物和鱼类分布的生物地层学和地理学分析; 3）陆地和淡水生态系统的古生物学研究。

AbstractCollaborative Research: Biotic diversity and vertebrate evolution inLate Devonian non-marine ecosystems of North AmericaNeil Shubin-EAR-0208377Edward Daeschler-EAR-0207721The Late Devonian (375-360 MYA) witnessed a burst of diversification of vertebrate life, including the origin of limbed vertebrates, and the elaboration of plants and invertebrates in terrestrial ecosystems. Accordingly, the description and analysis of Late Devonian vertebrates and ecosystems offers the ability to generate important data on the emergence of new taxa, new anatomical structures, new faunas, and new habitats during this critical moment of evolution. Our prior work (1993 to present) in the Late Devonian (Famennian Stage) Catskill Formation in Pennsylvania has produced well-preserved, highly diverse vertebrate assemblages from the same stratigraphic horizons as macrofossil plants, palynomorphs, arthropods, and bivalves. Exploratory work (1999-2000) in the Late Devonian (Frasnian Stage) Okse Bay Group in the Canadian Arctic has also revealed significantly fossiliferous units in this virtually unexplored region.This project will document and interpret the diversity of the non-marine parts of these Late Devonian systems in eastern North America. The temporal range will cover the Frasnian and Famennian Stages of the Late Devonian, a critical window in evolution. Fieldwork in the Famennian-age Catskill Formation has taken a significant step; the Pennsylvania Department of Transportation has given permission to remove a large wedge of overburden from the Red Hill locality, source of two early tetrapod taxa and a very diverse fauna and flora. Fieldwork in the Frasnian-age Okse Bay Group in the Canadian Arctic will focus on areas now recognized for their fossil productivity. The first major goal is the recovery, preparation and description of Late Devonian fossil material. Ensuing investigation of the phylogenetic affinities and stratigraphic position of fossil assemblages will allow both intraformational and global comparisons of biotic diversity. Assessment of intraformational stratigraphic relationships will enable an understanding of the biotic diversity in different portions of the fluvial systems. These analyses will inform: 1) higher level phylogenetic hypotheses of gnathostome vertebrates, 2) biostratigraphic and biogeographic analysis of the distribution of the Late Devonian tetrapods and fish, and 3) paleobiological investigation of the elaboration of terrestrial and freshwater ecosystems.