A Perfect Pterosaur: Pterodactylus scolopaciceps (n21) – part 4

Most pterosaur fossils are incomplete, crushed and disarticulated. By contrast, Pterodactylus scolopaciceps  BSP 1937 I 18 (Broili 1938, P. kochi n21 of Wellnhofer 1970, 1991, Fig. 1) is just the opposite, complete, uncrushed and articulated. Earlier we looked at the presence of a distinct naris, prior to that wing unguals and theday before that we documented vestigial manual digit 5.

Figure 1. Pterodactylus scolopaciceps  BSP 1937 I 18 (Broili 1938, P. kochi No. 21 of Wellnhofer 1970, 1991) complete, articulated and including soft tissue.

Figure 1. Pterodactylus scolopaciceps BSP 1937 I 18 (Broili 1938, P. kochi No. 21 of Wellnhofer 1970, 1991) complete, articulated and including soft tissue.

Today we’ll look at the soft tissue in this “perfect” specimen. There is a great deal of preparatory nicking on this specimen leaving skin impressions unmarked.

Soft tissue on Pterodactylus n21. Note the small patches anterior to the ankles, otherwise seen on Sharovipteryx. Patches of muscle or skin are present on the ribs. The high matrix in front and behind the elbow goes unexplained.

Figure 2. Soft tissue on Pterodactylus n21. Colors denote distinct membranes. Note the wing membrane is narrow at the elbow and attaches at mid thigh, as in ALL other pterosaurs. The uropatagia are separate and do not contact the tail. Note the small patches anterior to the ankles, otherwise seen on Sharovipteryx and previously overlooked. Patches of muscle or skin are present on the ribs. 

Pterosaur soft tissue is rarely preserved, but this specimen has it in spades from a throat sac to large and flat trapezius muscles (in pink) linking the neck to the shoulders and several other wing and leg membranes. As in all other known pterosaurs the wing membrane does not attach at the ankle, but becomes very narrow aft of the elbow (in cyan blue) before blending with the “fuselage fillet” next to the ribs and extending back to the thigh muscle. The propatagium (in violet) relaxes with the pteroid as the elbow flexes. A right uropatagium (in green) is very easy to see extending behind the right knee from above the ankle to the pelvis. The left one is tucked away. Small trim tab membranes (in amber) extend anterior to each ankle, as in Sharovipteryx (Fig. 3). These have been overlooked by all prior workers. The feet are webbed.

Sharovipteryx mirabilis

Figure 4. Sharovipteryx mirabilis in various views. Note the tiny pre-ankle extradermal membrane. Click to learn more.

A closer look at pedal digit 5
The conventional paradigm holds that pedal digit 5 in pterodactyloid-grade pterosaurs was reduced to a stub and in no pterosaurs was p5.3 (the ungual preserved). Earlier we found the ungual of pedal digit 5 on several specimens. The ungual is here (Fig. 5) on n21 as well, despite the vestigial size of the rest of the digit. In fact the ungual exceeds the length of m5.2, which in basal pterosaurs can be longer than the metatarsus. Here (Fig. 5) the metatarsus of pedal digit 5 is larger than the digit, which remains hyperflexed as in rhamphorhynchoid-grade pterosaurs.

Pedal digit 5 in Pterodactylus n21. The entire digit is present, only vestigial. Pedal 5.1 is partly covered my dermal membrane here. The green bone is mt5 with a hollow opening distally. Amber is p5.1. Blue is p5.2. Magenta is p5.3, the ungual.

Figure 5. Pedal digit 5 in Pterodactylus n21. The entire digit is present, only vestigial. Pedal 5.1 is partly covered my dermal membrane here. The green bone is mt5 with a hollow opening distally. Toe 5 is slightly disarticulated to reveal the distal condyle of mt5. Amber is p5.1. Blue is p5.2. Magenta is p5.3, the ungual, longer than p5.2 in this specimen.

This concludes our examination of n21, the perfect Pterodactylus. And this is why PterosaurHeresies.com was created, to expose problems and false paradigms in reptile paleontology, wherever they may arise.

Pterodactylus scolopaciceps.

Figure 2. Pterodactylus scolopaciceps. This image updates all prior versions. Click for more info.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Broili F 1938. Beobachtungen an Pterodactylus. Sitz-Bayerischen Akademie der Wissenschaten, zu München, Mathematischen-naturalischenAbteilung: 139–154.
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Pterodactylus

Manual digit 5 is present on both metacarpals. All the elements match one another.

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