Type species: Deilephila smaragditis Meyrick, 1899, by original designation.
DNA barcode data (although analyzed using the phenetic neighbor-joining method) and male genital morphology strongly suggest that, despite the marked differences in wing pattern, Tinostoma smaragditis is closely related to, and perhaps is even the sister-group of, Daphnis. The results of a preliminary and unpublished phylogenomic analysis (Rodolphe Rougerie, pers. comm.) appears to confirm this relationship, although the number of genes analysed for Tinostoma smaragditis is low compared to other taxa and it is placed on the end of a very long branch.
Tinostoma is not preoccupied by ‡Tinostoma Jousseaume, 1881, Bull. Soc. zool. Fr. 6: 182, which is an incorrect subsequent spelling of Teinostoma Adams, 1953 (Mollusca).