Amto–Musan was left unclassified by Ross (2005) (see Papuan languages#Ross (2005)) due to lack of data; Wurm (1975) had posited it as an independent family. The family has typological similarities with the Busalanguage isolate, but these do not appear to demonstrate a genetic relationship.
Timothy Usher links the Amto–Musan languages to their neighbors, the Arai languages and the Pyu language in as Arai–Samaia stock.[3]
Foley (2018) classifies them separately as an independent language family.[1] Foley also notes that due to heavy contact and trade with Left May languages, Amto–Musan languages have borrowed much cultural vocabulary from Left May.[1]
Cognates
Amto-Musan family cognates listed by Foley (2018):[1]
^ abcdefFoley, William A. (2018). "The Languages of the Sepik-Ramu Basin and Environs". In Palmer, Bill (ed.). The Languages and Linguistics of the New Guinea Area: A Comprehensive Guide. The World of Linguistics. Vol. 4. Berlin: De Gruyter Mouton. pp. 197–432. ISBN978-3-11-028642-7.