The steadfast tube-nosed fruit bat (Paranyctimene tenax) is a species of megabat in the family Pteropodidae found in West Papua, Indonesia, and Papua New Guinea. The species was first proposed as a subgeneric arrangement of Nyctimene, published as Nyctimene (Paranyctimene) tenax. The epithet tenax, derived from the Latin for 'steadfast', was intended to describe the conservation work of , whose retirement was announced when the new species was discovered. The subspecific epithet marculus, derived from Latin, translates as 'little hammer' and the diminutive form of Marc Argeloo's name, a dedication to his collections of bats for the Amsterdam Zoological Museum. Two subspecies were recognised by Mammal Species of the World (2005),