A New Look at the Phylogenetic Relationships Within Class Karyorelictea

The class Karyorelictea is characterized by simplified ciliary patterns and the inability of somatic nuclei to divide. Despite its importance for understanding ciliate life history, research in this group remains scarce and focused on species from the Northern Hemisphere. Here, we generated and analyzed sequences of SSU rDNA of six species of Karyorelictea collected in the coastal region of southern Brazil. Four of these species (morphologically assigned to Tracheloraphis) comprised a novel, well-supported clade within the family Trachelocercidae. Moreover, we observed extensive non-monophyly of genera Trachelocerca and Tracheloraphis, highlighting the need for a taxonomic revision of these taxa.