Definition of Platyhelminthes in English:


plural noun

  • A phylum of invertebrates that comprises the flatworms.

    • ‘Like other members of the phylum Platyhelminthes, those of the class Turbellaria are dorsoventrally compressed, with high surface area to volume ratios.’
    • ‘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).’
    • ‘The simplest animals that are bilaterally symmetrical and triploblastic (composed of three fundamental cell layers) are the Platyhelminthes, the flatworms.’
    • ‘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.’


Modern Latin (plural), from platy-‘flat’ + Greek helminth ‘worm’.