SGER: Predation in evolution: paleobiological consequences of cidaroid predation on crinoids

进化论中的捕食：捕食鹦鹉科动物的古生物学后果。来自澳大利亚蜥蜴岛和新西兰渐新世的证据。鲍米勒捕食通常被认为是自然选择的重要因素，化石记录中捕食者-猎物相互作用的研究使我们能够评估其进化影响。大量的工作致力于探索捕食在眼镜蛇生态和进化中的作用。例如，有人争辩说，在过去的大约100my(Bottjer和Amp；Jablonski，1988)中，有柄海百合转移到深水是捕食压力增加的结果，特别是来自破碎贝壳的鱼(Meyer&Amp；Macurda 1977；Meyer 1985；Oji 1996)。相比之下，有人提出，今天在浅水中繁衍的无柄龙虾之所以成功，是因为它们有能力应对捕食压力(Meyer&Amp；Macurda 1977)。在处理捕食压力方面的差异一般归因于柄海龙和海龙的脱落和再生能力以及后者的运动能力。然而，最近人们发现，今天S的优势类群--等甲类动物也能够快速爬行(Baumiller&Amp；Msing 2007)，这一特征通常与无茎节肢动物有关。它还表明，这些等分泌物容易受到杀戮类海胆的捕食(Baumiller等人。2008年)。作为与Cidarid相互作用的响应，等分泌物从茎的锚定端脱落，并从专注于脱落的茎部分的Cidarina爬行。这条？蜥蜴？S的尾巴？逃逸策略不仅将一系列行为特征(茎脱落和爬行)与捕食联系在一起，而且表明在评估海百合的生态和进化史时，需要考虑底栖捕食者，如捕食性天敌。这项研究的主要目的是确认直接替代杀虫类捕食棘突类动物(咬痕和骨折模式)的稳健性。这将包括研究活着的蜈蚣是如何用牙齿和肠道处理海鞘物质的。这项实验将在澳大利亚的蜥蜴岛研究站(LIRS)进行。同样在LIRS，还将探索其他潜在捕食者，如鱼类和甲壳类动物处理眼镜蛇物质的过程，以了解这些不同的捕食者是否在其眼镜蛇猎物的骨骼上留下独特的特征。在这项研究的实验部分之后，将探索化石记录，以寻找这种捕食者-猎物相互作用的历史证据。具体地说，将研究Kokoamu砂岩(新西兰南岛渐新世)的柄海百合，以寻找杀虫类损害的证据。科科阿木砂岩之所以被选中，是因为它含有丰富的珊瑚柱状化石，以及最近在其肠道中发现的具有菠萝石元素的Cidarid的遗迹--OrganoCidaris。如果成功，这项研究的结果将作为追求更大目标的基础：(1)通过研究已知与海鞘类棘球动物共生的地区的海鞘茎遗骸，探索这种相互作用的历史；(2)分析海鞘类的形态，寻找与茎脱落和爬行相关的特征；以及(3)在这些背景下，研究海鞘类的多样性趋势。特征和互动的频率。

Predation in evolution: paleobiological consequences of cidaroid predation on crinoids.Evidence from Lizard Island, Australia and the Oligocene of New ZealandT. K. BaumillerPredation is generally recognized as an important agent of natural selection and the study of predator-prey interactions in the fossil record allows us to evaluate its evolutionary impact. A large body of work has been devoted to exploring the role of predation in crinoid ecology and evolution. For example, it has been argued that the displacement of stalked crinoids to deep water over the past ~100my (Bottjer & Jablonski 1988) was the result of increased predation pressure, especially from shell-crushing fish (Meyer & Macurda 1977; Meyer 1985; Oji 1996). In contrast, it has been suggested that the success of the stalkless comatulid crinoids that today thrive in shallow water is due to their ability to deal with predation pressure (Meyer & Macurda 1977). The differences in handling predation pressure by stalked crinoids and comatulids have generally been attributed to the ability to shed and regenerate body parts and locomotory abilities of the latter. However, recently it has been discovered that today?s dominant group of stalked crinoids, the isocrinids, are also capable of rapid crawling (Baumiller & Messing 2007), a trait generally associated with stalkless comatulid crinoids. It also has been shown that these isocrinids are subject to predation by cidaroid sea urchins (Baumiller et al. 2008). In response to the interaction with a cidaroid, isocrinids shed the anchored end of the stalk and crawl away from the cidaroid which is preoccupied with the shed stalk portion. This ?lizard?s tail? strategy of escape not only links a set of behavioral traits (stalk shedding and crawling) to predation, but suggests that benthic predators, such as cidaroids, need to be considered in assessing the ecological and evolutionary history of crinoids. The major goal of this study is to confirm the robustness of a direct proxy for cidaroid predation on crinoids (bite marks and fracture patterns). This will involve studying how living cidaroids process crinoid material with their teeth and in their gut. This will be done experimentally at the Lizard Island Research Station (LIRS), Australia. Also at LIRS, the processing of crinoid material by other potential predators, such as fish and crustaceans, will be explored to see whether these different predators leave unique signatures on the skeletons of their crinoid prey. The experimental portion of the study will be followed by exploring the fossil record for historical evidence of this predator-prey interaction. Specifically, stalked crinoids of the Kokoamu Sandstone (Oligocene; South Island, New Zealand) will be studied for evidence of cidaroid damage. The Kokoamu Sandstone was chosen because it contains abundant crinoid columnals as well as remains of the cidaroid, Histocidaris, the very taxon which in the Recent was found with crinoid elements in its gut. If successful, the results of this study will serve as the basis for pursuing larger goals: (1) to explore the history of this interaction through geologic time by examining remains of crinoid stalks from localities where they are known to co-occur with cidaroid echinoids, (2) analyze the morphology of crinoids for traits associated with stalk shedding and crawling, and (3) examine diversity trends of crinoids in the context of these ?escapability? traits and the frequency of interaction.