Abstract Vase-shaped microfossils (VSMs) constitute a distinct group of fossils characteristic of late Tonian marine rocks. They often occur in high densities and in relatively diverse assemblages that include several morphotypes. All VSMs may have shared a test wall of similar structure and composition, as inferred from common patterns of preservation. However, little is known about the detailed morphology and structure of this wall. Here we examine the diversity, preservation, and wall morphology of a diverse assemblage of VSMs from the Russoya Member of the Elbobreen Formation in northeastern Spitsbergen. SEM imaging of exceptionally preserved specimens with their wall replicated in iron oxide reveals that these VSMs shared a well-defined, smooth, micrometre-thick wall ornamented with complex structures including facets, closed “pores”, and intricate relief patterns on the internal surface of the aperture. The observed similarities among different morphotypes suggest VSMs assemblages reflect the diversification of a single clade, likely related to the Arcellinida (Amoebozoa), an extant order to which they have been phylogenetically linked.

中文翻译：

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来自斯匹次卑尔根岛 Elbobreen 组 Russøya 段的形态多样的花瓶形微化石

摘要 花瓶形微化石 (VSMs) 构成了一组独特的具有晚托尼阶海相岩石特征的化石。它们通常以高密度和相对多样化的组合出现，包括几种形态类型。根据常见的保存模式推断，所有 VSM 可能共享一个具有相似结构和组成的测试墙。然而，人们对这堵墙的详细形态和结构知之甚少。在这里，我们研究了来自斯匹次卑尔根岛东北部 Elbobreen 组 Russoya 段的各种 VSM 组合的多样性、保存性和壁面形态。保存完好的标本的 SEM 成像显示，这些 VSM 具有明确的、光滑的、微米厚的壁，壁上装饰着复杂的结构，包括刻面、封闭的“孔”、以及孔内表面上复杂的浮雕图案。观察到的不同形态类型之间的相似性表明 VSM 组合反映了单个进化枝的多样化，可能与 Arcellinida（变形虫）有关，这是它们在系统发育上与之相关的现存秩序。