The Vannellidae are a family of Amoebozoa. During locomotion they tend to be flattened and fan-shaped, although some are long and narrow, and have a prominent clear margin at the anterior. In most amoebae, the endoplasm glides forward through the center of the cell, but vannellids undergo a sort of rolling motion with the outer membrane sliding around like a tank tread.
These amoebae are usually 10-40 μm in size, but some are smaller or larger. The most common genus is Vannella, found mainly in soils, but also in freshwater and marine habitats. Molecular phylogenies include them in the class Flabellinea as a sister group to the others, which have subpseudopodia.