Beipiaopterus (Lü 2002, 2003, Figs. 1, 2) is a roadkill pterosaur fossil that appears to have been physically crushed prior to burial. The radius and ulna are broken in half. There is a mass of soft wing tissue that definitely attaches to the hind limb and this has been used to “prove” that the wing membrane attached broadly to the tibia. That mass of soft tissue doesn’t really look like typical wing tissue, like the Zittel wing, unless it has been wadded up like an old receipt. There are also some long hairy parts, unlike typical wing membranes.
I’ve often wondered what was going on there with that soft tissue. Here we’ll take a good look at Beipiaopterus using DGS and see where it might fit on a reconstruction, something Lü (2002, 2003) did not attempt.
At first glance, it’s not at all clear what is happening with the soft tissue of Beipiaopterus, but manifestly clear that there is a mass of soft tissue there. So how can we interpret it?
Let’s make a reconstruction
If we put Beipiaopterus back together again (Fig. 2), perhaps we can find suitable places to move the soft tissue back into.
Given an understandable playing field (by straightening out the bones in a reconstruction), we can start placing the soft tissue “turf” where it seems to fit best. After all the soft tissue is a wadded up mess, just like the rest of the skeleton. Section A seems to be proximal hairy material. Section B seems to be midwing material and is attached to manual4.3. Section C seems to be wingtip material. Section D is definitely uropatagial as it attaches to the tibia and has a trailing edge.
Deep chord wing proof?
No. This specimen does not prove the wing membrane attached to the tibia, as Lü (2003) reported. Part of the wadded up membrane indeed does attach to the tibia, but that’s the uropatagium and it’s narrow. The rest is displaced wing tissue. We’ve seen displaced wing tissue on Sordes. And here’s an example of wing tissue just starting to tear from its mast (Fig. 3). Note how it starts to fold on itself.
Lü J-C. 2002. Soft tissue in an Early Cretaceous pterosaur from Liaoning Province, China. Memoir of the Fukui Prefectural Dinosaur Museum 1: 19-28.
Lü J-C 2003. A new pterosaur: Beipiaopterus chenianus, gen. et sp. nov. (Reptilia: Pterosauria) from Western Liaoning Province, China. Memoir of the Fukui Prefectural Dinosaur Museum 2: 153-160.
Lü J-C, Kobayashi Y, Yuan C, Ji S and Ji Q 2005. SEM Observation of the Wing Membrane of Beipiaopterus chenianus (Pterosauria). Acta Geologica Sinica 79:6 766-769.