The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on Quadrigyrus that would confirm its position as a unique order in the family Quadrigyridae.

[1] Quadrigyrus species consist of a proboscis covered in hooks and a long trunk.

[2] Q. torquatus has been found infesting the intestines of Ageneiosus caucanus and Hoplias malabaricus in the Magdalena River basin in Colombia.

This stage involves penetrating the wall of the mesenteron or the intestine of the intermediate host and growing.

There are no reported cases of Quadrigyrus infesting humans in the English language medical literature.