There is debate that this phylum should be split up because it is arguably polyphyletic.
There is debate that this phylum should be split up because it is arguably polyphyletic. This phylum, along with arthropods, and other smaller phyla, makes up a larger group called Ecdysozoa. These pseudocoelomates possess only longitudinal muscle cells, which they contract in order to move. Sydney Brenner did extensive work with one member of this phylum, and members of this phylum have four peripheral nerves that run along the length of its body; those nerves create a dense ring near the pharynx and serve as the brain. Name this phylum of roundworms which includes such organisms as C. elegans and hookworms.
There is debate that this phylum should be split up because it is arguably polyphyletic.
{nematoda}