Pterodactylus? spectabilis (TM 10341, no. 1 of Wellnhofer 1970) Late Jurassic ~175mya, ~10 cm snout-to-vent length was less than a third the size of and derived from a sister to the SMNS 50164 specimen of Dorygnathus and phylogenetically preceded a much larger pterosaur Beipiaopterus. Wellnhofer (1970) considered this specimen a juvenile Pterodactylus under the false assumption that pterosaurs, like archosaurs, changed proportions as they matured. We know from pterosaur embryos that they did not, but rather followed the isometric growth patterns found in the lepidosaur, Huehuecuetzpalli. Nevertheless, TM 10341 had "juvenile" SMNS 50164 proportions. Wellnhofer (1970) also considered this specimen a "pterodactyloid" due to its win proportions and apparent lack of a tail.

Distinct from the SMNS 50164 specimen of Dorygnathus, the skull of TM 10341 was relatively shorter, especially in the post-orbital region. The teeth were much smaller with none reaching "fang" status. Relative to the rest of the skeleton, the skull was larger and longer than the torso, following a trend initiated by SMN 50164 in which the skull was as long as the torso.

The sacral series was longer relative to the dorsal series. The caudals were reduced to tiny beads, but the same number of caudals appears to be present.

The ulna/radius were shorter relative to the humerus. The metacarpus appears unreduced relative to the carpus, but larger relative to the ulna. The fourth finger elements remained in proportion to the proximal wing.

The ilium was greatly elongated. The ischium was perforated. The prepubis plate extended posteriorly, the opposite of all preceding taxa.

See the pterosaur family tree 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.

Click to Enlarge. Dorygnathid skulls in phylogenetic sequence demonstrating the reduction to virtual disappearance of the naris. Jugal in blue. Nasal in green.

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