Germanodactylus is chiefly known from Solnhofen formation (Late Jurassic, Germany), but there’s one Germanodactylus that was found in the Niobrara formation of Kansas in the Late Cretaceous. And it was a big one (Fig. 1)!
Okay, I may have been a little misleading.
The Niobrara specimen has been formally named, Pteranodon occidentalis YPM 1179 (Marsh 1876a). The skull was twice the length (and therefore 8x the size of is nearest Germanodactylus sister, SMNK PAL 6592. But in the panoply of Pteranodon skulls (Fig. 2K), YPM 1179 had the shortest rostrum and ranks among the smallest otherwise. We don’t know the post-crania of YPM 1179. Did extreme metacarpals and shorter hind limbs evolve coincidentally with extreme rostral lengths? No one knows (but see below for clues). Those traits are the basic post-cranial attributes of Pteranodon that separate it from Germanodactylus (other than size). If YPM 1179 had longer legs and shorter metacarpals than a typical Pteranodon, then there would be even more argument to calling it a big Germanodactylus.
Did you know…
There’s more morphological variation among the various specimens of Germanodactylus (Fig. 3) than there is between SMNK PAL 6592 and YPM1179? Someday someone will sort out the real Germanodactylus from the non-Germanodactylus. It’s nearly as bad of a situation as the Pterodactylus sorting problem, reported on earlier here. And someone, hopefully, will confirm the separation of the eopteranodontids from the very similar azhdarchids seen here in the large pterosaur family tree. Experts are still confused about that one.
So, where do you draw the line?
Morphology? Size? Location? Tradition? They all have impact factors here in lumping or splitting these two sister taxa. YPM 1179 will probably remain a Pteranodon due to its separation in time and location. But now you and I both know, YPM 1179 is closer to Germanodactylus and forms a great transitional taxon to the Pteranodon clade (Fig. 1).
Mated with SMU 76476, the “oldest Pteranodon” (Myers 2010) we may have a clue as to the post-crania of YPM 1179 (Fig. 4). The humerus is relatively shorter in the SMU specimen. We don’t know how long the metacarpus and m4.1 were due to end breaks, but the metacarpus was at least slightly longer, as in Muzquizopteryx and Eopteranodon (Fig. 1).
The Deltopectoral Crest Warp
Pteranodon has a deltopectoral crest warp and thicker anteriorly. Myers (2010) reports, “The anterior edge of the terminal expansion of the deltopectoral crest is flat, and its long axis is oriented at an angle to the base of the crest, creating the distinctive warped appearance described by Padian (1984) and Bennett (1989).” Actually the warp in SMU 76476 is not as apparent and there is no thickness in the depth of the anterior deltopectoral crest found in other Pteranodon specimens. So, this humerus has a thin deltopectoral crest more like that of Germanodactylus.
Marsh OC 1876a. Notice of a new sub-order of Pterosauria. American Journal of Science, Series 3, 11:507-509.
Myers TS 2010. Earliest occurrence of the Pteranodontidae (Archosauria: Pterosauria) in North America: new material from the Austin Group of Texas. Journal of Paleontology 84(6): 1071-1081. PDF online