plagiopylida plagiopylida the plagiopylids are a small order of ciliates, including a few forms common in anaerobic habitats. plagiopylida scientific classification domain: eukaryota clade: diaphoretickes clade: tsar clade: sar clade: alveolata phylum: ciliophora subphylum: intramacronucleata class: plagiopyleasmall & lynn, 1985 order: plagiopylidajankowski, 1978 typical families plagiopylidae sonderiidae the body cilia are dense, and arise from monokinetids with an entirely unique ultrastructure; one or two rows of dikinetids run into the oral cavity, which takes the form of a groove, with a deep tube lined by oral cilia leading to the mouth. the order was introduced by eugen small and denis lynn in 1985, who treated it as a subclass of oligohymenophorea. since then they tend to be treated as an independent class, possibly affiliated with the colpodea. class plagiopylea is divided into two clades: one contains members of the order plagiopylida (like plagiopyla frontata and trimyema compressum) and the second clade contains plagiopylean ciliate associated with denitrifying obligate endosymbiont candidatus azoamicus ciliaticola.