Amoebae of the order Vannellida (Amoebozoa, Discosea) have a fairly recognizable spatulate, fan-shaped or semi-circular outlines and a wide area of frontal hyaloplasm. They can be easily distinguished from the other groups of lobose amoebae even by light microscopy. The dorsal side of these amoebae is usually smooth and rarely bears ridges or folds, which are never numerous or regular. We have isolated an unusual species of vannellid amoebae, called Vannella primoblina n. sp. from a terrestrial substrate. It has well-developed dorsal relief consisting of regularly appearing folds and ridges. This amoeba superficially resembles members of the genus Thecamoeba. However, molecular analysis showed that this strain belongs to the genus Vannella. This finding indicates that dorsal folds may also be a characteristic of some species of vannellid amoebae and probably are a functional detail of the cell morphology rather than an apomorphy of Thecamoebida lineage. Overall outlines of the cell and the presence of the expanded frontal hyaline area remains the most reliable characters used to differentiate vannellid amoebae from other gymnamoebae lineages.

Vannellida（Amoebozoa，Discosea）的变形虫具有相当容易辨认的呈扇形，扇形或半圆形轮廓，并且额叶透明质体面积大。即使通过光学显微镜，也可以很容易地将它们与其他类的变形虫区分。这些变形虫的背侧通常是光滑的，很少带有从未有很多或规则的脊或褶皱。我们已经分离出一种叫做Vannella primoblina n的不同寻常的Vannellid变形虫。sp。来自地面基质。它具有发达的背痛，包括规则出现的褶皱和隆起。该变形虫表面上类似于Thecamoeba属的成员。然而，分子分析表明该菌株属于Vannella属。。这一发现表明，背褶皱也可能是某些类香椿变形虫的特征，并且可能是细胞形态学的功能细节，而不是Thecamoebida谱系的无性形态。细胞的总体轮廓和扩大的额叶透明区域的存在仍然是最可靠的特征，可用于区分Vannellid amoebae和其他Gymnamoebae世系。