PDF(Pubmed)
Abstract：
The Ediacaran of Newfoundland preserves some of the oldest complex macroscopic communities, several of which are dominated by the fractal-like rangeomorph genus Fractofusus. Here we use computational fluid dynamics and a detailed reconstruction of Fractofusus misrai to document for the first time hydrodynamic phenomena associated with this sediment-reclining organism and its rangeomorph elements that are relevant to interpreting feeding strategies, explain the recently documented rheotropic growth oblique to currents, and provide insights into their impact on the Ediacaran seafloor. Obliquely oriented Fractofusus are common, likely representing a compromise between maximized aspect ratio and minimization of drag. Flow patterns on the upper surface of Fractofusus are consistent with the collection of dissolved and finely particulate nutrients, as well as gas exchange. Fractofusus produce a wake downstream, demonstrating that reclining rangeomorphs had potential to modify sedimentation patterns on the ancient seafloor by potentially allowing deposition of fine-grained sediment.
摘要：
纽芬兰的Ediacaran保留了一些最古老的复杂宏观群落，其中一些以分形状的范围形态属Fractofusus为主。在这里，我们使用计算流体动力学和对Fractofususmisrai的详细重建来首次记录与这种沉积倾斜的生物相关的水动力现象及其与解释摄食策略相关的范围形态元素，解释最近记录的与电流倾斜的流变生长，并提供有关它们对Ediacaran海底影响的见解。斜向Fractofusus是常见的，可能代表最大化纵横比和最小化阻力之间的折衷。Fractofusus上表面的流动模式与溶解和细颗粒营养素的收集一致，以及气体交换。Fractofusus在下游产生尾流，证明倾斜的地形有可能通过允许细粒沉积物的沉积来改变古代海底的沉积模式。
