Soon afterwards, Hermann von Meyer classified the same specimen as the new genus and species Gnathosaurus subulatus, a name which came to be universally used shortly thereafter.

In the 1860s, scientists such as Albert Oppel compared the G. subulatus jaw fragment to contemporary pterosaurs such as Pterodactylus and Ctenochasma, and concluded that it was also probably a "flying reptile" rather than a crocodilian.

It probably lead a lifestyle akin to that of modern spoonbills, wading with its jaws open and closing them upon touching small prey.

[2] Possible juvenile specimens of G. subulatus may be known from several complete skeletons that had previously been classified as the separate species Pterodactylus micronyx.

In the analysis, they recovered both species of Gnathosaurus (G. subulatus and G. macrurus) within the family Ctenochasmatidae, more precisely within the subfamily Gnathosaurinae, as sister taxa.