Aposturisoma myriodon is a species of armored catfish. It is the only species in the genus Aposturisoma. The generic name derives from Greek apo- meaning "outside", German sturio meaning "sturgeon" and Greek soma meaning "body"; the whole referring to its outwardly similar appearance to a sturgeon. Aposturisoma myriodon is native to South America, the Aguaytia River basin in the Upper Amazon River drainage. This species is only known from its type location. This species is rheophilic, preferring to live in shallow, fast waters with a rubble substrate.