Order EUGLYPHIDA Copeland 1956, emend. Cavalier-Smith 1997
Test of organic material; most taxa with secreted silica scales held together by an organic cement; tubular mitochondrial cristae.
Euglyphidae Wallich 1864, emend. Lara et al., 2007
Test with thin elliptical scales; presence of specialized scales around the pseudostome with typical indentation.
Assulinidae Lara et al. 2007
Acrostome test composed of elliptic plates disposed in a regular, alternate pattern; test strongly compressed; no specialized type of scales around pseudostome.
Assulina, Placocista, Valkanovia.
Trinematidae Hoogenraad & De Groot 1940, emend Adl et al. 2012
Test with bilateral symmetry; scales oval or round, sometimes of both types; specialized tooth-shaped scales around the aperture; aperture invaginated in some taxa.
Corythion, Playfairina, Puytoracia, Trinema.
Sphenoderiidae Chatelain et al, 2013
Test with self-secreted circular to elliptical silica scales of different sizes and shapes, but without indentations; pseudostome surrounded with small round or oval scales; usually its ventral side shorter.
Cyphoderiidae De Saedeleer 1934
Scales circular, oval or kidney-shaped, juxtaposed or imbricated; test aperture angled, some with collar.
Campascus, Corythionella, Cyphoderia, Messemvriella, Pseudocorythion, Schaudinnula.
Paulinellidae De Saedeleer 1934, emend. Adl et al. 2012
Pyriform, uncompressed shape; scales, when present, long, with length perpendicular to aperture. At least two genera (Ovulinata, Micropyxidiella ) with totally organic test without silica scales.
Ovulinata, Paulinella, Micropyxidiella.
Euglyphida: Ampullataria, Deharvengia, Euglyphidion, Heteroglypha,Matsakision, Pareuglypha, Pileolus, Sphenoderia, Tracheleuglypha, Trachelocorythion.