Tubulinea

Tubulinea are a group of amoeboid organisms characterized by their ability to form temporary cytoplasmic extensions called pseudopodia, which they use for movement and feeding. This type of locomotion, known as amoeboid movement, is considered a primitive form of animal movement. Tubulineans can be either naked or enclosed in a protective shell called a test. They are distinguished by their capacity to produce tubular, subcylindrical pseudopodia and typically lack centrosomes and flagellated stages. Amoeboid movement itself involves the polymerization of actin and myosin proteins, which drives the flow of cytoplasm to propel the organism.123