The ichnogenera Syringomorpha and Daedalus are here interpreted as products of infaunal biofilm harvesters. This study investigated: (1) Syringomorpha nilssoni and Syringomorpha isp. from the Cambrian Series 2-Miaolingian Campanario Formation, northwest Argentina; and (2) Daedalus halli from the Floian Grès et Schistes de la Cluse de l'Orb Formation, Montagne Noire, France. Syringomorpha nilssoni occurs in sandy to mixed intertidal to lower shoreface deposits, whereas Syringomorpha isp. in the lower intertidal zone. Daedalus halli occurs in a lagoon and intertidal to lower shoreface sands of a barrier island. Syringomorpha and Daedalus comprise a vertical J-shaped causative burrow and deep spreite. These ichnotaxa form monospecific assemblages (bioturbation index BI = 3–5) in quartzose medium- to fine-grained sandstone, recording colonization in high-energy tide- and wave-dominated settings. Lower abundances (BI = 1–2) are observed in silty sandstone. The abundance of both ichnogenera in mature sandstone is inconsistent with a classic deposit-feeding strategy because ‘clean’ sediments are commonly impoverished of organic detritus, this being particularly true in Cambro-Ordovician littoral settings lacking terrestrial plant detritus. Based on morphology, host sediment properties and comparison with modern structures, such those produced on intertidal and shallow subtidal setting by Arenicola marina and Paraonis fulgens, it is suggested that the diet of Syringomorpha and Daedalus producers may have consisted of biofilms colonising sand grains, associated eukaryotic microbes, and possibly meiofauna. Whereas Syringomorpha is a product of the Cambrian explosion, Daedalus is associated with the Ordovician Radiation. In contrast to most ichnotaxa, which display long temporal ranges, these two ichnogenera are restricted to the Cambrian and Ordovician-Silurian, respectively. The underlying reasons for the relatively restricted stratigraphic ranges of these ichnotaxa are unclear, but space competition, and increased predation pressure may have played a role. The feeding strategy of the Daedalus and Syringomorpha producers was less efficient than suspension feeding and passive predation, trophic types epitomized by the dominant macroinfauna that persisted in water-agitated nearshore sands during the rest of the Phanerozoic.

中文翻译：

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早古生代沿海环境中的生物膜收割机

ichnogenera Syringomorpha和Daedalus在这里被解释为动物生物膜收割机的产物。本研究调查了： (1) Syringomorpha nilssoni和Syringomorpha isp。来自阿根廷西北部寒武系2-苗岭期坎帕纳里奥组；(2)来自法国黑山的 Floian Grès et Schistes de la Cluse de l'Orb 组的Daedalus halli 。Syringomorpha nilssoni出现在沙质到混合潮间带到下滨面沉积物中，而Syringomorpha isp. 在潮间带下部。Daedalus halli出现在泻湖和潮间带到屏障岛的较低海岸沙子中。Syringomorpha和Daedalus包括一个垂直的 J 形致病洞穴和深精灵。这些 ichnotaxa 在石英砂中到细粒砂岩中形成单一特异性组合（生物扰动指数 BI = 3-5），记录了在高能潮汐和波浪主导环境中的定殖。在粉砂岩中观察到较低的丰度（BI = 1-2）。成熟砂岩中两种 ichnogenera 的丰度与经典的沉积物供给策略不一致，因为“清洁”沉积物通常缺乏有机碎屑，在缺乏陆地植物碎屑的寒武纪-奥陶纪沿岸环境中尤其如此。基于形态、宿主沉积物性质和与现代构造的比较，例如在潮间带和浅潮下带环境中产生的构造Arenicola marina和Paraonis fulgens，建议 Syringomorpha 和 Daedalus 生产者的饮食可能包括定殖沙粒的生物膜、相关的真核微生物和可能的小型动物。Syringomorpha是寒武纪大爆发的产物，而Daedalus与奥陶纪辐射有关。与显示长时间范围的大多数 ichnotaxa 相比，这两个 ichnogenera 分别限于寒武纪和奥陶纪-志留纪。这些 ichnotaxa 相对有限的地层范围的根本原因尚不清楚，但空间竞争和捕食压力增加可能起到了作用。Daedalus和Syringomorpha生产者的摄食策略效率低于悬浮摄食和被动捕食，这些营养类型是占主导地位的大型动物的缩影，在显生宙的其余时间里，它们在水搅动的近岸砂中持续存在。