Pterodactylus? kochi? MB.R.3530.1 No. 40

Pterodactylus? kochi (Zittel, 1882; No. 40 of Wellnhofer, 1970) MB.R.3530.1 Late Jurassic ~160 mya ~3 cm skull length, was originally considered a juvenile Pterodactylus. Here it nests between St/Ei I and Ctenochasma elegans, a primitive ctenochasmatid.

Distinct from St/Ei I, the skull of No. 40 was longer wth small, anterolaterally protruding teeth. The rostrum was longer. The postorbital region was shorter.

The cervicals were slightly longer. The torso was much longe due principally to the extension of the sacrals. The caudals were reduced and shortened.

The sternal complex was larger, comprising half of the pre-prepubis area. The humerus extended to the ilium. Manual 3.1 was longer than m2.1.

The ilium was longer, in concert with the increased sacral length. The femur was shorter and shorter than the increased tibia. The pes was as long as the tibia. Distinct from the R156 specimen of Dorygnathus, digiti V was shorter than mt IV.

The dorygnathid tree is here. The pterosaur family tree is here.

The phylogenetic size reduction following Angustinaripterus. As in other pterosaur clades, a size reduction preceded a size increase with a novel morphology. In this case a size reduction preceded the ctenochasmatids. Ctenochamatids with shorter jaws and fewer teeth were more primitive, not juveniles of larger, toothier specimens. By not including tiny pterosaurs in prior phylogenetic studies these important transitions were missed.

JPM 2014-004 was incorrectly referred to Gladocephaloideus by Lü et al. 2016). Here it nests between n40 and Gnathosaurus + AMNH 5147. Like Gladocephaloideus, the JPM specimen has a long neck and long rostrum, but the other traits nest the JPM specimen as shown here. This hints at a wide radiation at the genesis of this clade.

Lü J, Kundrát M, Shen C 2016. New Material of the Pterosaur Gladocephaloideus Lü et al., 2012 from the Early Cretaceous of Liaoning Province, China, with Comments on Its Systematic Position. PLoS ONE 11(6): e0154888. doi:10.1371/ journal.pone.0154888

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

Dorygnathus

Angustinaripterus

St/Ei I

n40

Ctenochasma clade

Ctenochasma elegans

C. elegans AMNH 5147

Gnathosaurus

C. elegans n45

Gegepterus

Ctenochasma gracile n65

Pterodaustro