“…The four classes formerly grouped in C10 are most commonly symbionts of vertebrates. Monocercomonas (once a large genus, later proven to be polyphyletic and redefined in its current form by Čepička et al., 2010 and Hampl et al., 2007) has only been molecularly detected in squamate hosts (Tuska‐Szalay et al., 2022); Tritrichomonas has instead been found in various kinds of tetrapods (Tachezy et al., 2002); Dientamoebea genera are symbionts of birds or humans, and one not‐yet‐barcoded genus, Protrichomonas , was also reported from fish (Brugerolle & Lee, 2000; Mantini et al., 2009; Stark et al., 2016). Simplicimonadea as defined here includes two subgroups: Simplicimonas , confirmed in squamates and bugs (Čepička et al., 2010; Smejkalová et al., 2014), and a clade of termite (Kalotermitidae and Archotermopsidae) symbionts including the putative Tricercomitus (Taerum et al., 2018).…”