👉 Protosteliids are a group of protozoan worms that have been discovered in the fossil record. They belong to the family Platyhelminthes and are characterized by their small size, which is typically less than 1 millimeter (0.4 inches) long, and their ability to attach themselves to hard surfaces through specialized structures called spines or striae. These protozoans play a crucial role in the digestive processes of certain animals and have been used as experimental models for
