Thecochaos fibrillosum (Greeff, 1891) Page, 1981

Diagnosis: Locomotive form usually broad, irregular; branched only when changing direction. Surface with wrinkles. Anterior hyaloplasm as a crescentic cap. Multinucleate, up to one hundred; each nucleus ovoid or spherical, with central nucleolus.

Dimensions: 160 to 320 µm in length, nucleus 7.0-10.8 µm.

Habitat: Freshwater.

Remarks: This species was discovered by Angie Opitz in Tirol.