Tetrahelia (from Latin tetra- 'four' and helio- 'sun') is a genus of four-ciliated heterotrophic heliozoan protist. It is the only genus in the family Tetraheliidae, order Axomonadida, class Endohelea and subphylum Endohelia. It is a monotypic genus, containing the sole species Tetrahelia pterbica, previously classified as Tetradimorpha pterbica.

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