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

合作研究：北美泥盆纪晚期非海洋生态系统中的生物多样性和脊椎动物进化Neil Shubin-EAR-0208377 Edward Daeschler-EAR-0207721晚泥盆世(375-360 MYA)见证了脊椎动物生命多样性的爆发，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详细描述。因此，对泥盆纪晚期脊椎动物和生态系统的描述和分析提供了在这一进化的关键时刻产生关于新的类群、新的解剖结构、新的动物群和新的生境的重要数据的能力。我们之前的工作(1993年至今)在宾夕法尼亚州晚泥盆世(法门期)卡茨基尔建造，从与大型化石植物、孢粉化石、节肢动物和双壳类相同的地层层位产生了保存完好、高度多样化的脊椎动物组合。加拿大北极奥克斯湾群在晚泥盆世(弗拉斯期)的勘探工作(1999-2000年)也在这个几乎未被勘探的区域发现了大量化石单元。该项目将记录和解释北美东部晚泥盆世系统的非海相部分的多样性。时间范围将涵盖晚泥盆世的弗拉斯期和法门期，这是演化的关键窗口。法门时代的卡茨基尔地层的实地考察工作已经迈出了重要的一步；宾夕法尼亚州交通部已经批准从红山地区移走一大块楔形覆盖层，那里是两个早期四足动物分类群的来源，以及非常多样化的动植物。加拿大北极弗拉斯尼亚时代的奥克斯湾群的实地考察工作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、制备和描述晚泥盆世化石物质。随后对化石组合的系统发育亲缘关系和地层位置的调查将使生物多样性的地层内和全球范围内的比较成为可能。层内地层关系的评估将使人们能够了解河流系统不同部分的生物多样性。这些分析将提供以下信息：1)更高层次的颌口脊椎动物系统发育假说；2)晚泥盆世四足动物和鱼类分布的生物地层和生物地理分析；3)陆地和淡水生态系统阐述的古生物学调查。

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.