Final proof could only be given by a continuous growth series, as previously has been done in the case of Rhamphorhynchus and Pterodactylus. Provisionally Padian kept distinguishing two species, but moved two specimens to C. zitteli: SMNS 51100 and GPIT 24470, because of their larger size and morphological similarities.
To confirm identification, a continuous growth series was required, as has been used for Rhamphorhynchus and Pterodactylus in the past. Initially, Padian classified these specimens as separate species but later moved two specimens (SMNS 51100 and GPIT 24470) to C. zitteli due to their larger size and similar features.