| Ventricleftida | |
|---|---|
| Scientific classification | |
| Domain: | Eukaryota |
| Supergroup: | Rhizaria |
| Phylum: | Cercozoa |
| Subphylum: | Filosa |
| Class: | Thecofilosea |
| Order: | Ventricleftida Cavalier-Smith in Howe et al. 2011 |
| Families | |
|
And see text | |
| Diversity | |
| 6 species | |
Ventricleftida is an order of thecate zooflagellates. The order belongs to class Thecofilosea and contains six species across two families and two genera. They were previously considered tectofilosids. The order's name comes from "venter" meaning belly and "cleft", because of the ventral cleft.
Ventricleftids are a group of strongly flattened oval zooflagellates. Scales are nonexistent, extrusomes and rigid theca are present. Two unequal flagella emerge subapically, often from apical notch. Posterior flagellum helps gliding on surfaces. Branched filose pseudopods for feeding emerge from ventral cleft that are separate from and behind the flagellar groove, unlike thaumatomonads and Auranticordis.
The genera Ventrifissura and Verrucomonas were described in 2010, each containing two species. They were added to order Tectofilosida. In 2011, these two genera were transferred to a new order called Ventricleftida in class Thecofilosea and phylum Cercozoa. Its name comes from "venter" meaning belly and "cleft", because of the ventral cleft. In 2018, two families were created for two genera, Ventrifissuridae for Ventrifissura and Verrucomonadidae for Verrucomonas. In 2020, two new species of Ventrifissura were described.
A phylogenomic analysis in 2026 recovered Ventricleftida as the most basal group within Thecofilosea. Chlamydophryidae is represented by Katarium.