Nipponopsalididae is a family of harvestmen with three described species in one genus, Nipponopsalis, which is found in East Asia.

The pedipalps and legs are very long and slender, and the chelicerae are longer than their body and heavily sclerotized.

[4] They can be distinguished from other long-jawed Dyspnoi, like Ischyropsalis, Taracus, and Oskoron, by the complete absence of any spines on the second thoracic segment, though they are not known to be sympatric with any of those genera.

[2] This family is very geographically conserved, and is known only from East Asia, primarily the four main Japanese islands.

[5] Synonym: Ischyropsalis abei Sato & Suzuki, 1939 This subspecies is known from the three Japanese islands of Honshu, Kyoshu, and Shikoku.

This subspecies has more swollen male cheliceral apophyses and considerably shorter legs than N. abei longipes.

The male chelicerae in this species exhibit a unique, notable protuberance basally on the second segment.

[10] In addition, the penis shaft is shorter and broader than that of the other species, with a proportionally larger glans.

[5] Synonym: Ischyropsalis yezoensis Suzuki, 1958 This species was discovered in Akan National Park, in Hokkaido.