Heterolobosea

Heterolobosea are a group of organisms that exhibit characteristics of both amoebas and flagellates. They are protists, which are predominantly unicellular eukaryotic organisms. Some heteroloboseans are free-living in various environments like fresh water, salt water, or soil, while others are parasitic.12

A notable parasitic example is Histomonas meleagridis, which causes enterohepatitis, or blackhead disease, in poultry. These organisms can be amoeba-like, possessing pseudopodia (cytoplasmic extensions), and may also have flagella for movement. Some members of the order Heterochlorida, which are plantlike flagellates, can also be amoeboid during certain life cycle stages.23