Euglenids are a diverse group of euglenozoan flagellates that includes phototrophs, osmotrophs, and phagotrophs. Despite making up most of the phylogenetic diversity of euglenids, phagotrophs remain understudied, and recent work has focused on ‘deep-branching’ groups. Spirocuta is the large clade encompassing all flexible euglenids including the phototroph and primary osmotroph clades, plus various phagotrophs. Understanding the phylogenetic diversity of phagotrophic spirocutes is crucial for tracing euglenid evolution, including how phototrophs arose. We used single-cell approaches to greatly increase sampling of SSU rDNA for phagotrophic euglenids, particularly spirocutes, including the first sequences from Urceolus, Jenningsia, Chasmostoma, and Sphenomonas, and expanded coverage for Dinema and Heteronema sensu lato, amongst others. Urceolus monophyly is unconfirmed. Organisms referred to Jenningsia form two distinct clades. Heteronema vittatum and similar cells branch separately from Heteronema (c.f.) globuliferum and Teloprocta/Heteronema scaphurum, while Dinema appears as 2–3 clades. Sphenomonas is monophyletic and the deepest branch within Petalomonadida. The census of genera markedly underestimates the phylogenetic diversity of phagotrophs, but taxonomic restraint is necessary when sequences are not available from type species or reasonable surrogates. SSU rDNA phylogenies do not resolve most deep relationships within Spirocuta, but identify units of diversity to sample in future multigene analyses.

蓝藻类是真鳞动物鞭毛的不同种类，包括光养性，渗透性和吞噬性。尽管组成了桉树的大部分系统发育多样性，但吞噬菌仍未被充分研究，并且最近的工作集中在“深支”人群。Spirocuta是一个大型进化枝，涵盖了所有柔韧性的黄粉虫，包括光营养生物和原渗营养生物，以及各种吞噬生物。理解吞噬营养的螺旋藻的系统发育多样性对于追踪藻类的进化至关重要，包括光养生物的产生方式。我们使用单细胞方法极大地增加了吞噬营养性尾状花序（特别是螺旋菌）的SSU rDNA采样，包括来自Urceolus，Jenningsia，Chasmostoma和Sphenomonas的第一个序列，并扩大了Dinema和Heteronema sensu lato等的覆盖范围。未确认过熊ce。提到詹宁西亚的生物形成两个不同的分支。Heteronema vittatum和类似细胞分别分支Heteronema（CF）globuliferum和Teloprocta / Heteronema scaphurum，而Dinema显示为2-3进化枝。细单胞菌是单生的，在Petalomonadida中是最深的分支。属的普查显着低估了吞噬菌的系统发育多样性，但是当无法从类型物种或合理的替代物获得序列时，必须进行分类学上的限制。SSU rDNA系统发育不能解决Spirocuta中最深层的关系，但可以识别多样性单位，以便在将来的多基因分析中进行采样。