The excavates are a group of flagellate protozoa, including both free-living and symbiotic forms, some of which are important parasites. They typically have two or more flagella inserted at the anterior of a ventral feeding groove supported by microtubules. Some have mitochondria with discoid cristae, but many lack them entirely. The following lines are included here:
- Retortamonads
- Diplomonads
- Malawimonas
- Trimastix
- Carpediemonas
- Jakobids
- Heterolobosea