Data from: The macro- and microfossil record of the middle Cambrian priapulid Ottoia

The stem-group priapulid Ottoia Walcott, 1911, is the most abundant worm
in the mid-Cambrian Burgess Shale, but has not been unambiguously
demonstrated elsewhere. High-resolution electron and optical microscopy of
macroscopic Burgess Shale specimens reveals the detailed anatomy of its
robust hooks, spines and pharyngeal teeth, establishing the presence of
two species: Ottoia prolifica Walcott, 1911, and Ottoia tricuspida sp.
nov. Direct comparison of these sclerotized elements with a suite of
shale-hosted mid-to-late Cambrian microfossils extends the range of
ottoiid priapulids throughout the middle to upper Cambrian strata of the
Western Canada Sedimentary Basin. Ottoiid priapulids represented an
important component of Cambrian ecosystems: they occur in a range of
lithologies and thrived in shallow water as well as in the deep-water
setting of the Burgess Shale. A wider survey of Burgess Shale macrofossils
reveals specific characters that diagnose priapulid sclerites more
generally, establishing the affinity of a wide range of Small Carbonaceous
Fossils and demonstrating the prominent role of priapulids in Cambrian
seas.

干群曳鳃动物（stem-group priapulid）奥托虫（Ottoia Walcott, 1911）是中寒武世布尔吉斯页岩（Burgess Shale）中丰度最高的蠕虫类生物，但目前尚未在其他地点得到明确证实。对布尔吉斯页岩大型标本开展的高分辨率电子与光学显微成像分析，揭示了其粗壮钩、棘与咽齿的精细解剖结构，据此确立了两个有效物种：丰产奥托虫（Ottoia prolifica Walcott, 1911）与三齿奥托虫（Ottoia tricuspida sp. nov.）。将上述硬化骨片与一套赋存于页岩中的中-晚寒武世微体化石进行直接比对，将奥托类曳鳃动物的分布范围拓展至加拿大西部沉积盆地（Western Canada Sedimentary Basin）的中-上寒武统地层中。奥托类曳鳃动物是寒武纪生态系统的重要组成类群：它们广泛产出于多种岩性地层中，不仅在浅水环境中繁盛，同时也存续于布尔吉斯页岩所代表的深水沉积环境。对布尔吉斯页岩大型化石的更全面调查，揭示了一批可通用诊断曳鳃动物硬化骨片的形态特征，由此明确了大量小型碳质化石（Small Carbonaceous Fossils）的分类亲缘关系，并证实了曳鳃动物在寒武纪海洋中发挥的重要生态作用。