Arm waving in stylophoran echinoderms: three-dimensional mobility analysis illuminates cornute locomotion
Arm waving in stylophoran echinoderms: three-dimensional mobility analysis illuminates cornute locomotion
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DOI：
10.1098/rsos.200191
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发表时间：
2020-06-10
影响因子：
3.5
通讯作者：
Briggs, Derek E. G.
中科院分区：
文献类型：
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作者：
Clark, Elizabeth G.;Hutchinson, John R.;Briggs, Derek E. G.
化石无脊椎动物的运动策略通常解释的基础上的形态描述。然而，已经表明，在现存的无脊椎动物中具有不同形态的同源结构不一定与它们的运动能力的差异相关。在这里，我们提出了一种新的方法来分析运动的化石无脊椎动物与刚性骨架通过调查的cornute stylophoran，一个灭绝的化石棘皮动物与神秘的形态，使其运动模式难以重建。我们确定了一个stylophoran臂的运动范围的基础上数字化的三维形态的早奥陶世的形式，Phyllocystis crassimarginata。我们的分析表明，有效的手臂向前epifaunal运动的基础上，背腹运动，如以前假设的角stylophorans，是不可能的，这个分类群的运动主要是由横向运动的近端Aulacophore驱动的可能性更大。三维数字建模为阐明化石无脊椎动物的运动能力和运动策略提供了客观而严格的方法。
The locomotion strategies of fossil invertebrates are typically interpreted on the basis of morphological descriptions. However, it has been shown that homologous structures with disparate morphologies in extant invertebrates do not necessarily correlate with differences in their locomotory capability. Here, we present a new methodology for analysing locomotion in fossil invertebrates with a rigid skeleton through an investigation of a cornute stylophoran, an extinct fossil echinoderm with enigmatic morphology that has made its mode of locomotion difficult to reconstruct. We determined the range of motion of a stylophoran arm based on digitized three-dimensional morphology of an early Ordovician form, Phyllocystis crassimarginata. Our analysis showed that efficient arm-forward epifaunal locomotion based on dorsoventral movements, as previously hypothesized for cornute stylophorans, was not possible for this taxon; locomotion driven primarily by lateral movement of the proximal aulacophore was more likely. Three-dimensional digital modelling provides an objective and rigorous methodology for illuminating the movement capabilities and locomotion strategies of fossil invertebrates.