Cycloneuralia is a proposed clade of ecdysozoan animals including the Scalidophora (kinorhynchans, loriciferans, priapulids), the Nematoida (nematodes, nematomorphs), and the extinct palaeoscolecids. It may be paraphyletic, or may be a sister group to Panarthropoda. Or perhaps Panarthropoda is paraphyletic with respect to Cycloneuralia. The group has also been considered a single phylum, sometimes given the old name Nemathelminthes. The uniting character is the nervous system organization with a circumpharyngeal brain and somata–neuropil–somata pattern.
The name derives from the position of the brain around the pharynx.