Together with Radiolaria, Heliozoa is a diverse group of protists characterized by radiating cellular projections called axopodia. Both groups are polyphyletic, with almost all main radiolarian and heliozoan lineages having been placed in different parts of the eukaryotic tree. One notable exception is the centrohelid heliozoans, the last large axopodia-bearing assemblage that remains of enigmatic evolutionary origin. Centrohelids are predatory protists very common in freshwater and soil habitats, and can also occur widely in marine environments. Phylogenies based on the 18S rRNA have notoriously failed to infer the evolutionary relationships of centrohelids to other eukaryotes, even the use of multiple protein-coding genes was unsuccessful at pinpointing a robust origin. Thus far, however, only one small transcriptome dataset for centrohelids is available, leading to 2 main shortcomings in the phylogenetic reconstructions: 1) the centrohelid diversity was not captured in earlier multigene-based inferences; 2