Definition of Platyhelminthes in English:
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.
Definition of Platyhelminthes in:
- British & World English dictionary