The Interference Avoidance Hypothesis and Scaling Principles in Crinoids

9706071鲍米勒棘鸟是古代海洋环境的重要组成部分，其多样化的形态保存了极好的记录，所描述的900多个属证明了这一点。然而，尽管它们的重要性和多样性，我们对它们的进化史和古生态学的解释是有限的，许多问题仍然没有答案。本研究将解决两个问题：i)分层模型(Ausich，1980)中隐含的预测是否得到同一物种个体的空间分布模式的支持？2)什么结构或功能规则支配着茎海葵的生长？为了解决第一个问题，分级模型(Ausich，1980)中隐含的一个预测，即海百合的同级上游邻居干扰摄食，应该避免干扰，将通过量化活体等分泌物的空间分布模式进行检验。这些模式将通过数字化从潜水器上拍摄的照片进行量化。一阶预测指出，如果资源有限，由于相同物种的个体使用相同的资源，应该避免上游邻居，或者应该位于某个关键距离之外。现场标本和流动槽中的标本的操作将被用来进一步评估海兔是否主动地避免干扰。对这一假设的另一项测试将涉及通过潜水器收集几只白纹伊蚊的个体，将它们标记并重新部署到一个小区域，并分阶段监测它们的分布模式；非随机模式将支持这一假设。种内回避假说的一个古生物学预测是，表征回避的空间分布格局应该仅在能够重新定位的分类群(例如：高级分支、节)中表达，而不是在那些永久附着在底物上的分类群中表达。对这一预测的测试将涉及OBT从埋葬地平线(例如：Legrand、Burlington、Crawfordsville)的单一层面(例如：Legrand、Burlington、Crawfordsville)获得同一物种完整个体的空间分布数据，并确定该模式是否不同于随机模式以及是否与回避假设一致。所有这些方法的结果将为评估水动力状况和营养限制等因素对眼镜蛇自古学以及可能的进化史的相对重要性提供基础。为了确定是结构规则还是功能规则支配海鞘形态，将测量化石类群和潜水器收集的现存海鞘的茎长、直径和臂长。将这些数据与基于几何、应力和弹性三种比例模型的预测进行比较，以确定观察到的数据是否支持任何一种模型。鬼针草-。它们是嗜血者，它们的取食姿势需要茎有一定的弯曲，根据弹性相似模型预测这些小圆球的比例。如果这一预测适用于这类甲壳动物，即那些具有“标准”生态的甲壳动物(利用抛物线过滤扇形姿势的流变者)，那么将对被认为具有不寻常生态系统的化石分类群(钙甲科、金鱼科、五角科)进行检查，以确定它们是否根据不同于弹性相似性的规则进行缩放。该项目的顺利完成将解决海绵体功能形态的一些主要问题，并检验一个重要的生态和古生态模型--分层模型。尽管眼镜蛇是这里的焦点，但所开发的方法具有更广泛的影响。例如，支配海绵状形态的原则也应该适用于其他水生嗜血菌的生长。

9706071 Baumiller Crinoids were an important component of ancient marine environments and an excellent record of their diverse morphologies has been preserved, as is demonstrated by over 900 described genera. Yet 'm spite of their importance and diversity, our interpretations of their evolutionary history and paleoecology are limited and many questions remain unanswered. Two problems will be tackled in this study: I)are the predictions implicit 'm the tiering model (Ausich, 1980) supported by the pattern of spatial distribution of individuals of the same species? And 2) what structural or functional rules govern the growth of stalked crinoids? To tackle the first problem, one prediction implicit in the tiering model (Ausich, 1980), namely that the same-tier, upstream neighbors of crinoids interfere with feeding and that interferences should be avoided, will be tested by quantifying the patterns of spatial distribution of a living isocrinid, Neocrinus decorus. The patterns will be quantified by digitizing photos taken from a submersible.A first-order prediction states that if resources are limiting, since individuals of the same species utilize the same resources upstream neighbors should be avoided or should lie beyond some critical distance. Manipulations of in situ specimens and specimens 'm a flow tank will be used to further assess whether crinoids actively avoid interference. Another test of this hypothesis will involve collecting several 'individuals of N. decorus by submersible, tagging and redeploying them onto a small area, and episodically monitoring their pattern of distribution; a non-random pattern would support the hypothesis. A paleontological prediction of the intraspecific avoidance hypothesis is that the spatial patterns of distribution characterizing avoidance should be expressed only among taxa capable of relocation (e.g.: advanced cladids, articulates), but not among those taxa permanently attached to the substrate. Tests of this prediction will involve obt aining data on the spatial distribution of complete individuals of the same species from a single bedding plane of a burial horizon (e.g.: LeGrand, Burlington, Crawfordsville) and determining whether the pattern differs from random and is consistent with the hypothesis of avoidance. Results of all these approaches will provide a basis for assessing the relative importance of factors such as hydrodynamic regime and nutrient limitations to crinoid autecology and, possibly, evolutionary history. To determine if structural or functional rules govern crinoid morphology , stalk length and diameter and arm length will be measured for fossil taxa and for extant crinolds collected by submersible. Comparison of these data to predictions based on three scaling models, geometric, stress, and elastic, will be used to determine if the observed data support any of the models. Stalked crinoid-. which are rheophiles utilize a feeding posture which requires a certain flexure of the stalk, and these crinolds are predicted to scale according to the model of elastic similarity. If that prediction is home out for such crinoids, i.e., those with "standard" ecologies (rheophiles utilizing a Parabolic Filtration Fan Posture), fossil taxa thought to have had unusual ecologies (calceocrinids, Seirocrinus, Pentacrinus) will be examined to determine if they scaled according to rules different from elastic similarity. A successful completion of the project will solve some major problems of crinoid functional morphology and test an important ecological and paleoecological model, that of tiering. Although crinoids are the focus here, the methods developed have broader implications. For example, the principles governing crinoid morphology should also govern the growth of other aquatic rheophiles.