What worms have an ovoid flat shape body?

Worms with an ovoid flat shape body primarily belong to the phylum Platyhelminthes, commonly known as flatworms. This group includes various classes such as planarians, flukes, and tapeworms. Their flattened bodies allow for increased surface area, which aids in respiration and nutrient absorption. Examples include species like the common planarian (Dugesia) and the liver fluke (Fasciola hepatica).