The Dapingian to Darriwilian Kanosh Formation is one of the most fossiliferous units of the Pogonip Group (Great Basin, western US). It records a critical phase of the so-called Great Ordovician Biodiversification Event (GOBE) during which many marine clades diversified on lower systematic levels. However, a comprehensive palaeoecological analysis has not been presented for this unit so far. Based on newly collected material from three sections in the type area at Ibex, we reconstruct benthic marine communities, analyse diversity patterns, and discuss its significance for the GOBE. We find no differences in species’ composition across the formation with respect to brachiopods. Benthic assemblages are dominated by Shoshonorthis michaelis, alongside the presence of Anomalorthis lonensis and Anomalorthis utahensis across the whole unit. Trilobites show a more pronounced facies restriction with species of Kanoshia and Pseudomera being observed in more proximal limestone whereas Bathyurellus and Pseudoolenoides occur in fine-grained, low-energy deposits. The skeletal limestone also records abundant bioclasts of bryozoans, echinoderms, and receptaculitids, suggesting an ecologically diverse and tiered community being present in the inner shelf zone. However, most of these groups are not particularly diverse in terms of species richness. This implies that principle establishment of typical members of the “Palaeozoic Fauna” is not associated with a local diversification of clades. The comparably low habitat diversity of the Kanosh Fauna likely reflects environmental constraints such as high rates of siliclastic input. Additionally, these mainly Dapingian communities still represent a base-line fauna before the principal diversification took place.

大坪阶至达里维尔阶卡诺什组是波戈尼普群（美国西部大盆地）中化石含量最高的单元之一。它记录了所谓的大奥陶纪生物多样化事件（GOBE）的关键阶段，在此阶段许多海洋进化枝在较低的系统水平上进行了多样化。但是，到目前为止，尚未对该单元进行全面的古生态分析。基于在伊比克斯典型地区三个地区新收集的资料，我们重建了底栖海洋群落，分析了多样性模式，并讨论了其对GOBE的意义。我们发现整个腕足类的物种组成没有差异。底栖动物群以Shoshonorthis michaelis为主，并与Anomalorthis lonensis并存。和整个单元上的犹他州异常。三叶虫显示出更明显的相限制，在更近端的石灰岩中观察到了Kanoshia和Pseudomera的物种，而Bathyurellus和Pseudoolenoides发生在细颗粒，低能量的沉积物中。骨骼的石灰岩还记录了苔藓，棘皮动物和受体的大量生物破灭，这表明在内层架带区域存在着生态多样性和分层的群落。但是，这些物种中的大多数在物种丰富度方面并不是特别多样化。这意味着“古生代动物群”典型成员的原则建立与本地进化枝的多样性无关。卡诺什动物区系的生境多样性相对较低，可能反映了诸如硅质碎屑输入率高等环境限制。此外，在主要的多样化发生之前，这些主要的大坪阶社区仍然代表着基线动物群。