The subclass Peniculia (Oligohymenophorea, Intramacronucleata) is one of the most known groups of the phylum Ciliophora, being composed by very notorious representatives, such as Paramecium and Frontonia. Nevertheless, phylogenetic relationships among genera within this subclass are still far from being resolved. Moreover, for several members of the group the characterization by molecular markers is still lacking, such as for Wenrichia, Clathrostoma, Paraclathrostoma, Didieria and, to date, also for Neobursaridium. The finding of one strain of Neobursaridium gigas from India led to the first molecular characterization of this uncommonly sampled ciliate. The 18S rDNA sequence and the COI sequence were obtained and used for phylogenetic analyses. Moreover, the partial mitochondrial genome of N. gigas was sequenced, annotated and employed for phylogenomics analysis. To increase the sampling effort for the Paramecium clade, several newly obtained 18S rDNA sequences of parameciids are herein presented. Unexpectedly, the inclusion of N. gigas's molecular data in phylogenetics/phylogenomics analyses did not help to solve the complex evolution relationships inside Peniculia. Conversely, it raised new and intriguing questions about Paramecium phylogeny, since N. gigas clustered inside Paramecium clade as sister species of Paramecium bursaria in all the performed analyses. A critical revision of past and present data led to rename N. gigas as Paramecium gigas (Balech, 1941) comb. nov., and triggered the revision of genus Paramecium, with the proposal of the new subgenus Gigaparamecium subgen. nov. Hypotheses on the evolution of giant morphologies in ciliates are also discussed.

中文翻译：

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新法氏囊的系​​统发育重塑草履虫（低聚纲，纤毛虫）的系统学

青霉亚类（Oligohymenophorea，Intramacronucleata）是纤毛门的最著名的群体之一，由非常臭名昭著的代表组成，例如草履虫和Frontonia。尽管如此，该亚类属之间的系统发育关系仍远未解决。此外，对于该组中的几个成员，仍然缺乏通过分子标记物进行表征，例如对文氏菌属，阴茎肉瘤，副锁骨肉瘤，Didieria以及迄今为止的新球囊菌。一株新巨嘴鸟的发现来自印度的结果导致了这种罕见采样的纤毛虫的第一个分子表征。获得了18S rDNA序列和COI序列，并将其用于系统发育分析。此外，测序了N. gigas的部分线粒体基因组，对其进行了注释并用于系统发育组学分析。为了增加对草履虫的进化枝的取样工作，本文提出了几种新近获得的草履虫的18S rDNA序列。出乎意料的是，将N. gigas的分子数据包括在系统发育/系统发育分析中，无助于解决青霉菌内部的复杂进化关系。相反，自从吉氏猪笼草以来，它引起了有关草履虫系统发育的新的和有趣的问题。在所有进行的分析中，草履虫在草履虫的进化枝中聚集在一起，成为草履虫的姐妹种。由于对过去和现在的数据进行了严格的修订，因此将吉氏猪笼草改名为草履虫（Paramecium gigas）（Balech，1941年）。11月，并根据新的Gigaparamecium亚属的提议引发了Paramecium属的修订。十一月 还讨论了纤毛虫中巨形态进化的假说。