The Pterosaur Wing Membrane
1. The Background
The first sensible reconstruction of a pterosaur skeleton and wing shape was made by Samuel Thomas von Soemmering in 1812. The reconstruction assumed a few missing features from the skeleton and a wing membrane was extrapolated from what was known about bats and flight at that time.
It was not until 1873 that the wing structure was known from the fossil record. A specimen originally named Rhamphorhynchus phyllurus was discovered in the Lithographic Shale of Bavaria. This specimen was later reclassified as Rhamphorhynchus muensteri. At about the same time an isolated wing known as the Zittel wing was also published. Both fossils showed the outline and structure of the wing membrane of Rhamphorhynchus.
The wing membrane is soft tissue and it will only be preserved in the very finest sediments in anaerobic conditions, where the animal is silted up and buried very rapidly. These conditions existed in the Lithographic Limestone of Bavaria in Germany and they can be found in a few other places world wide. Such finds are very rare.
With additional finds, the wing membrane became progressively better understood.
Terms to note;
Patagium - the general term for the whole of the
Propatagium - the wing membrane in front of the wing bones, associated with the pteroid bone.
Actinopatagium - the main wing membrane with actinofibrils providing strength and form.
Picnofibrils - hair like structures observed near the body and at the wing tips in some pterosaurs.