Spironematellidae (previously known as Spironemidae) 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.

Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes.

Classification

The classification of Spironematellidae, as of 2022:

Spironematella multiciliata
  • Hemimastix Foissner, Blatterer & Foissner, 1988 H. amphikineta Foissner, Blatterer & Foissner, 1988 H. kukwesjijk Eglit & Simpson, 2018
  • Stereonema Foissner & Foissner 1993 non Kützing 1836 S. geiseri Foissner & Foissner 1993
  • Spironematella Silva 1970 emend. Shɨshkin 2022 (=Spironema Klebs 1893 non Vuillemin 1905 non Léger & Hesse 1922 non Rafinesque 1838 non Hochst. 1842 non Lindley 1840 non Meek 1864) S. multiciliata (Klebs 1892) Silva 1970 (=Spironema multiciliatum Klebs 1893) S. terricola (Foissner & Foissner 1993) Shɨshkin 2022 (=Spironema terricola Foissner & Foissner 1993) S. goodeyi (Foissner & Foissner 1993) Shɨshkin 2022(=Spironema goodeyi Foissner & Foissner 1993)