Trinema scutarius  Siemensma et Łuców, 2025

Diagnosis. Shell ovoid, circular in cross-section, colorless to dark brown. Large body scales are discus-shaped, touching or slightly overlapping each other, and smaller scales are circular to oblong. Aperture circular, invaginated and bounded by an irregular row of small denticulate apertural scales.

Dimensions: According to Łuców et al. (2025): Shell length 54.3—76.2 µm; width 25.6—39.9 µm; depth 26.3—39.3 µm; aperture 8.0-14.0 µm; large scales 7.0—14.2 µm.

Habitat: Freshwater, peatland.

Geographical distribution: Type locality: Khar Zurkhnii Khukh Nuur fen, Mongolia.

Differential diagnosis. Trinema scutarius differs from all known Trinema species by its large, thick and relatively few scales, and its rough and often colored appearance which is not common for the genus.

References: Łuców, D., Siemensma, F., Avirmed, D., Obremska, M., Słowiński, M., Zawiska, I., 2025. Morphological and morphometric investigations on testate amoebae from Mongolia with descriptions of a new genus and four new species. European Journal of Protistology 97, 126128. https://doi.org/10.1016/j.ejop.2024.126128