Hyoliths are extinct enigmatic organisms of early lophotrochozoan affinity known globally from the Palaeozoic Era and were especially diverse and abundant in the Cambrian Period. However, the commonly incomplete preservation of hyolith exoskeletons and our limited knowledge of their soft anatomy makes their ecological and biological aspects unclear. Konservat-Lagerstätte are crucial windows to unlock the mysteries of hyoliths. Here we report a new occurrence of exceptionally preserved hyolithid hyoliths from the middle Cambrian Mantou Formation (Miaolingian, Wuliuan) in Shandong Province, North China. The preserved soft organs of the new species Novakotheca weifangensis sp. nov. include a U-shaped gut and possible pharynx, oesophagus, stomach and digestive gland, which provide significant new information for the reconstruction of the digestive system of hyolithids. Two taphonomic modes of hyoliths described herein are recognized: soft tissue preservation through pyritization and three-dimensional shell preservation through phosphatization. Morphological variations due to different preservational pathways in the same species are revealed, highlighting the taphonomic bias on taxonomy. The ecological association between hyoliths and small brachiopod epibionts is a direct example of species interactions, providing insights into the ecological structures and adaptability of early animals during Cambrian time.

中文翻译：

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保存完好的华北中寒武统的石榴石

Hyoliths 是早在古生代时代就已广为人知的具有早期 Lophotrochozoan 亲和力的已灭绝的神秘生物，在寒武纪时期尤其多样化和丰富。然而，hyolith 外骨骼的普遍保存不完整以及我们对其软解剖学的有限知识使得它们的生态和生物学方面尚不清楚。Konservat-Lagerstätte 是解开冰石之谜的关键窗口。在这里，我们报告了华北山东省中寒武统馒头组（苗岭期，五六县）新发现的保存完好的冰晶石。新物种保存下来的软器官潍坊新树sp。十一月 包括U形肠道和可能的咽、食道、胃和消化腺，它们为水石虫消化系统的重建提供了重要的新信息。本文所述的冰晶石的两种埋藏模式得到认可：通过黄铁矿化保存软组织和通过磷酸盐化保存三维壳。揭示了由于同一物种的不同保存途径导致的形态变化，突出了分类学上的埋藏偏差。hyoliths 和小型腕足类动物之间的生态关联是物种相互作用的直接例子，为寒武纪早期动物的生态结构和适应性提供了见解。