RUI: Analysis of an Early-Middle Devonian Ecosystem: Trout Valley Formation, Maine

瑞：分析早-中泥盆世生态系统：Trout Brook，Main罗伯特·加斯塔尔多和罗伯特·E·纳尔逊Ear-0087433缅因州的鲑鱼谷地层保留了为数不多的早-中泥盆世(埃米西亚-艾菲利亚)时期的陆地生态系统之一。它已被用作早期陆地群落结构的初步模型，其中镶嵌着机会主义植物居住在景观中。人们认为这些植物是克隆的，主要是因为这些植物的有性繁殖被认为是相对罕见的(基于营养植物和含孢子囊的植物之间的比例)。在这种植物镶嵌中，植物和动物之间的相互作用被限制在碎屑摄食上，这是根据动物的形态、藻类分布和植物损害的性质推断的。对这一景观的解释是基于很少公布的野外数据，其中的环境背景和沉积环境以前被解释为微咸水三角洲环境。似乎没有什么证据支持这一环境背景，也没有挖掘数据支持生态重建。这项拟议的研究将由地质学专业的本科生作为高级独立项目进行，包括实地和实验室研究。本科生将测试四个假设，重点是：(1)鲑鱼谷地层序列；(2)植物化石组合的挖掘特征；(3)相关的陆地大型无脊椎动物和早期生态系统结构；以及(4)这些组合中可能记录的植物-动物相互作用。学生将建立一个环境框架，以便将化石组合放置在其中，以便更准确地了解它们的起源；限制露头带内组合的动植物分类特征，从中可以产生更现实的古环境重建；以及调查早-中泥盆世记录的动植物相互作用的进化水平。

RUI: Analysis of an Early-Middle Devonian Ecosystem: Trout Brook, MaineRobert Gastaldo and Robert E. NelsonEar-0087433The Trout Valley Formation, Maine, preserves one of the few terrestrial ecosystems of the Early to Middle Devonian (Emsian-Eifelian) age. It has been used as the prima facie model of early terrestrial community structure in which a mosaic of opportunist plants populated the landscape. It is thought that these plants were clonal mainly because sexual reproduction in these plants is thought to be relatively rare (based upon the ration between vegetative and sporangium-bearing plants). Within this vegetational mosaic, interactions between plants and animals was restricted to detritus feeding, as deduced from animal morphologies, coprolite distribution, and the nature of plant damage. The interpretation of this landscape is based upon scant published field data, of which the environmental context and depositional setting has been interpreted previously as a brackish delta setting. There appears to be little evidence to support this environmental context, and there are no taphonomic data to support the ecological reconstruction. The proposed research will be conducted by undergraduate majors in Geology as senior independent projects that include both field and laboratory studies. Undergraduates will test four hypotheses focusing on: (1) the stratigraphic sequence of the Trout Valley Formation: (2) the taphonomic signature of plant fossil assemblages; (3) the associated terrestrial macroinvertebrates and early ecosystem structure; and (4) the plant-animal interactions that may be recorded in these assemblages. Students will develop an environmental framework in which the fossil assemblages can be placed for a more accurate understanding of their genesis; constrain the plant and animal taphonomic signatures of the assemblages within the outcrop belt from which a more realistic paleoenvironmental reconstruction can be produced; and investigate the evolutionary level of plant-animal interactions recorded in the Early-Middle Devonian.