Orthonychiformes

Orthonychiformes is a proposed order of birds that has been suggested to encompass a single family, Orthonychidae, which contains the genus Orthonyx. This genus includes three species of ground-dwelling birds native to New Guinea and northeastern Australia: the New Guinea logrunner, the Papuan logrunner, and the Australian logrunner. These birds are characterized by their strong legs and feet, adapted for scratching through leaf litter in search of invertebrates. They are generally dull in coloration, with males of some species exhibiting brighter plumage.

The phylogenetic placement of Orthonychiformes has been a subject of debate among ornithologists. Traditionally, they were often placed within the passerine suborder Passeri, but their exact relationships have been unclear. Some studies have suggested a closer affinity with the family Pomatostomidae (Australasian babblers), while others have indicated a more distant relationship. More recent molecular studies have placed the Orthonychidae within the infraorder Passerida, though their precise position within this large group is still being investigated. The order Orthonychiformes itself is not universally recognized, with some researchers preferring to classify Orthonyx as incertae sedis or within a broader babbler-like assemblage. Further research is ongoing to clarify the evolutionary history and taxonomic position of these unique birds.