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

摘要北美晚泥盆世非海洋生态系统的生物多样性与脊椎动物进化在晚泥盆世（375-360 MYA）是脊椎动物多样性的爆发时期，包括有肢脊椎动物的起源，以及陆地生态系统中植物和无脊椎动物的发展。因此，对晚泥盆纪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新分类群、新解剖结构、新动物群和新栖息地的重要数据的能力。我们之前的工作（1993年至今）在宾夕法尼亚州的晚泥盆世（famonian Stage）卡茨基尔组（Catskill Formation）中发现了保存完好、高度多样化的脊椎动物组合，这些脊椎动物来自与大型化石植物、巨形动物、节肢动物和双壳类动物相同的地层层位。1999-2000年，加拿大北极地区晚泥盆世（弗拉斯纪）的Okse湾群的勘探工作也在这个几乎未被勘探过的地区发现了重要的化石单位。该项目将记录和解释北美东部晚泥盆世系统非海洋部分的多样性。时间范围将涵盖晚泥盆纪的弗拉斯和法门尼亚阶段，这是进化的一个关键窗口。famium -age Catskill组的野外工作取得了重要进展；宾夕法尼亚州交通部已经批准从红山地区移除一大块覆盖层，红山地区是两种早期四足动物类群和非常多样化的动植物群的来源。在加拿大北极地区弗拉斯尼亚时代的奥克塞湾群的实地考察将集中在现在被认为具有化石生产力的地区。第一个主要目标是恢复、准备和描述晚泥盆世的化石材料。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信息和全球比较成为可能。对信息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。这些分析将有助于：1)对颌口脊椎动物进行更高层次的系统发育假设；2)对晚泥盆世四足动物和鱼类分布进行生物地层学和生物地理学分析；3)对陆地和淡水生态系统进行古生物学研究。

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.