Quadrulella vas Cerda, 1986

Description. Shell yellowish, compressed, elongated, with a rounded fundus, and a well-separated neck in broad view. Neck length ca. 1/3rd of whole test, with a clear constriction at its base (as in Apodera vas), giving the impression of a bicameral test. Plates generally not overlapping, except along the constriction at the base of the neck. Pseudostome with an organic lip.

Dimensions: According to Cerda (1986): Shell length 250–360 µm; width 150–170 µm; aperture 17—18.5 µm wide (n=7).

Habitat: Mosses.

Geographical distribution: Peru.

Remarks: Kosakyan et al. (2016) conducted a phylogenetic study of genus Quadrulella based on mt-COI sequence data, suggesting the inclusion of Q. vas into the list of incertae sedis species, as it may represent a separate genus

References: Kosakyan, A., Lahr, D.J.G., Mulot, M., Meisterfeld, R., Mitchell, E.A.D., Lara, E., 2016. Phylogenetic reconstruction based on COI reshuffles the taxonomy of hyalosphenid shelled (testate) amoebae and reveals the convoluted evolution of shell plate shapes. Cladistics 32, 606–623. https://doi.org/10.1111/cla.12167

Kosakyan, A., Meisterfeld, R., Lara, E., Duckert, C., Mitchell, E., 2025. A taxonomic monograph of hyalospheniid testate amoebae. Amoebozoa: Arcellinida: Hyalospheniformes, Mémoire XIV. Éditions Alphil-Presses universitaires suisses, Neuchâtel.