A phylum of invertebrates that comprises the flatworms.
- ‘However, opinions do differ for the scoring of three phyla in particular: Platyhelminthes, Nemertea, and Rotifera (variously scored as primitively possessing or lacking a prototroch).’
- ‘For example, both the Nematoda and Platyhelminthes contain obligate parasites as well as free-living species.’
- ‘Frontal glands have been cited in the classical literature as probable homologues of Platyhelminthes and nemerteans.’
- ‘Like other members of the phylum Platyhelminthes, those of the class Turbellaria are dorsoventrally compressed, with high surface area to volume ratios.’
- ‘The simplest animals that are bilaterally symmetrical and triploblastic (composed of three fundamental cell layers) are the Platyhelminthes, the flatworms.’
Modern Latin (plural), from platy- ‘flat’ + Greek helminth worm.