[2] P. aznari was found infesting a long-billed curlew (Numenius americanus) from northern Mexico.

[3] Prosthorhynchus Kostylew, 1915 contains many species: P. cylindraceus was found infesting the Austral thrush (Turdus falcklandii) in central Chile.

[4] Janice Moore[5] discovered P. cylindraceus to be a parasite that infects an intermediate host, the terrestrial isopod Armadillidium vulgare, which alters its behavior and becomes more susceptible to P. cylindraceus' primary host, the European starling (Sturnus vulgaris).

Lueheia Travassos, 1919 contains several species: L. inscripta was found infesting the Austral thrush (Turdus falcklandii) in central Chile.

Golvan, 1957 Schmidt and Kuntz, 1967 Johnston, 1929 S. macropisthospinus has been found in the intestine of the tiger (Panthera tigris) and a water monitor (Varanus salvator) in Vietnam.