Pterodactylus? kochi (Wagner 1837 Ornithocephalus? kochi von Meyer 1859, B St ASXIX 3 (plate) SMF No. R 404 (counterplate), No. 23 of Wellnhofer 1970) was 2.5 times taller and derived from No. 12. No. 23 phylogenetically preceded Germanodactylus rhamphastinus, No. 64.

Distinct from No. 12, the skull of No. 23 was sharper, the jugal was deeper, the teeth were larger and the mandible was deeper.

The torso was deeper. The dorsal ribs were more robust. The sacrals were relatively larger.

Manual 4.3 approaches the elbow. The wing, when folded, barely reaches the top of the cervicals.

The pelvis was relatively larger.

Embryo pterosaurs indicate that juveniles were much more like the adults than prior workers guessed. Thus, smaller pterosaur specimens with with distinct morphologies are distinct taxa.

The family tree of the Ornithocephalia and Germanodactylia is here. The expanded family tree of the Pterosauria is here. Size comparisons between No. 23, No. 12 and No. 6 can be found here and here.

Several correct and incorrect assignments to Pterodactylus. Click to enlarge. Many of these taxa (specimens) were assigned to the genus Pterodactylus by Wellnhofer (1970) and other authorities before the advent of computer assisted phylogenetic analysis and before most of them were graphically reconstructed and scaled to make comparisons easier. Furthermore, these assignments were made under the false assumption that pterosaurs, like mammals and archosaurus (including crocs and birds) changed as they matured, developing a relatively longer snout and smaller eye. Embryo pterosaurs demonstrate that relatively little changed during maturity, especially in the proportions of the skull.

von Meyer CEH 1859. Zur Fauna der Vorwelt. Vierte Abt.: Reptilien aus dem lithographischen Schiefer des Jura in Deutschland und Frankreich.1. Lieferung: 1–84 & pls, 1859 and 2. Lieferung: 85–114 & pls, 1860. Frankfurt am Main: H. Keller. [pp. 7–90, 141–144 & pls 1–10.]

Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Pterodactylus