Stereonema
Spironematellidae
Family of heterotrophic flagellates, in the group Hemimastigophora
Spironematellidae (previously known as Spironemidae)[1] is a family of heterotrophic flagellates, in the group Hemimastigophora. They vary in size and shape from the ellipsoid Hemimastix amphikineta (14 × 7 μm) to the vermiform Spironematella terricola (43 × 3 μm), and are united by the possession of two rows of cilia, called kineties.[2]
Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes.[3][4]