Sabellida is a well-known clade containing tube-dwelling annelid worms with a radiolar crown. Iterative phylogenetic analyses over three decades have resulted in three main clades being recognized; Fabriciidae, Serpulidae and Sabellidae, with Fabriciidae proposed as the sister group to Serpulidae. However, relationships within Sabellidae have remained poorly understood, with a proliferation of genera. In order to obtain a robust phylogeny with optimal support, we conducted a large-scale phylogenomic analysis with 19 new sabellid transcriptomes for a total of 21 species. In contrast to earlier findings based on limited DNA data, our results support the position of Fabriciidae as sister taxon to a Sabellidae + Serpulidae clade. Our large sampling within Sabellidae also allows us to establish a stable phylogeny within this clade. We restrict Sabellinae to a subclade of Sabellidae and broaden the previously monotypic Myxicolinae to include Amphicorina and Chone. We tested the robustness of species tree reconstruction by subsampling increasing numbers of genes to uncover hidden support of alternative topologies. Our results show that inclusion of more genes leads to a more stable topology with higher support, and also that including higher divergence genes leads to stronger resolution.

Sabellida是一种著名的进化枝，其中包含具管冠状的居住在管中的类线虫。经过三十年的反复系统进化分析，已识别出三个主要进化枝。i科，Ser科和虎耳科，其中proposed科为the科的姊妹组。然而，Sabellidae内的关系仍知之甚少，而且属也大量增加。为了获得最佳支持的强大系统发育，我们对19种新的sabellid转录组进行了大规模的系统进化分析，共21种。与基于有限DNA数据的早期发现相比，我们的研究结果支持了Fabricidaidae作为Sabellidae + Serpulidae进化枝的姊妹分类群的地位。我们在Sabellidae中的大量采样也使我们能够在此进化枝中建立稳定的系统发育。Amphicorina和Chone。我们通过对越来越多的基因进行二次采样以揭示替代拓扑结构的隐藏支持，来测试物种树重构的鲁棒性。我们的结果表明，包含更多的基因会导致具有更高支持的更稳定的拓扑结构，而且包含更高的发散基因会导致更强的分辨率。