The family was restricted to the Northern Hemisphere, living in the warm temperate and paratropical forest belt that covered portions of Eurasia and North America.

[3][4] As noted by Günter Bechly and Karin Wolf-Schwenninger in 2011, the defining characteristic shared by all members of the family is the placement of the forewings m1, m2 and m3 cells in a triangular pattern.

When reviewing the snakefly fossil record in 2002, paleoentomologist Michael S. Engel noted the lack of convincing distinctions between the two families, but tentatively retained the separation.

The subfamily can be distinguished from other mesoraphidiids by presence of a short stigma with a single cross-vein and the forewing possessing triple branching of the CuA, R and M veins.

[3] The remaining genera of the family were placed into a third subfamily, Mesoraphidiinae, all with the shared character of a Sc vein which ends about midway towards the wingtip and a pterostigma that does not have any crossveins.

Cantabroraphidia, Grimaldiraphidia, Lebanoraphidia and the type genus Nanoraphidia share a group of distinct traits such as their overall minute size, the postorbital region of the head is shortened and the Rs vein in the wing with one or no forks.