The genus Caliechthrus is possible monotypic taxon with a single species - White-crowned cuckoo
The white-crowned cuckoo or white-crowned koel (Cacomantis leucolophus) is a species of cuckoo in the family Cuculidae. It was originally described by Salomon Müller as Cuculus leucolophus. It was later placed in the monotypic genus Caliechthrus, but most taxonomists place it the genus Cacomantis because it has a similar song to other cuckoos in this genus and it is genetically similar to the pallid cuckoo (Cacomantis pallidus). It is found in New Guinea and neighbouring Salawati Island.