†Monocheilus Resser 1937 (trilobite)
Trilobita - Asaphida - Dikelocephalidae
Parent taxon: Dikelocephalidae according to P. A. Jell and J. M. Adrain 2003
Sister taxa: Briscoia, Dikelocephalus, Princetonella, Pterocephalops, Stigmacephalus
Subtaxa: Monocheilus anatinum, Monocheilus micros
Ecology: fast-moving low-level epifaunal deposit feeder