Sharovipteryx skull revised

In response to an interested reader, J. Headden, I spent the day looking at and tracing the head and neck of Sharovipteryx, attempting to identify the skull parts. I used phylogenetic bracketing to determine what shapes I should be looking for, especially in the palatal elements. I present them here as large as they will show in WordPress.

Sharovipteryx in situ. See figure 2 for identification of elements and figure 3 for a reconstruction.

Figure 1. Sharovipteryx in situ. See figure 2 for identification of elements and figure 3 for a reconstruction. Lots of skin here. Note the neck skin is 6x wider than the cervicals. Stretched out by those long hyoids and this loose skin becomes a taut set of strakes, aerodynamic pitch controls. Are those pycnofibers, collagen or wrinkles on the neck? They look like fibers to me. And do you see the insect inside the antorbital fenestra? Guide graphics in figure 2.

DGS Digital Graphic Segregation
The DGS tracing (Fig. 2) reveals the elements of the crushed skull, including some palatal elements that have shifted to the side. There is a winged insect there, lacking one wing, in the antorbital fenestra. There are other insects, mostly beetles, elsewhere on the slab and the site is known for its insects. Somer workers dismiss DGS, but no one else has found the details presented here using traditional microscope, prism and pencil tools.

I wanted to present a much larger image in order for readers to determine for themselves if the neck structures were hairs, wrinkles or collagen. To my mind these are elongated fibers, overlapping others. The specimen is buried slightly in the matrix. If there are stray hairs hidden below the matrix, they have yet to be exposed.

Earlier we discussed the use of this 6x wider neck skin as an aerodynamic strake used during gliding.

Figure 2. Skull of Sharovipteryx with elements identified from figure 1. Yes that's a winged insect in the middle of the left antorbital fenestra. The hairs on the right are possible matrix artefacts, possible pycnofibers. Judge for yourself what the various fiber-like shapes represent. I think they're pycnofibers.

Figure 2. Skull of Sharovipteryx with elements identified from figure 1. Yes that’s a winged insect in the middle of the left antorbital fenestra. The hairs on the right are possible matrix artefacts, possible pycnofibers. Judge for yourself what the various fiber-like shapes represent. I think they’re pycnofibers.

Reconstruction from graphic elements
Here (Fig. 3) the colored elements are arranged according to their identities to check fit and create a reconstruction in several views.

Figure 3. Elements of Sharovipteryx skull reconstructed in palatal and lateral views. Elements identified in figure 2.

Figure 3. Elements of Sharovipteryx skull reconstructed in palatal and lateral views. Elements identified in figure 2.

Yes, there could be some mistakes. This tracing differs from prior versions. If you find problems, please alert me to them. At this point no one else on the planet has attempted a precise reconstruction of the skull of Sharovipteryx based on examination of the specimen. The fact that my reconstruction changes over time is not an indictment of DGS, but a measure of my increasing experience and judgement.

Figure 5. Reconstruction of Sharovipteryx skull in several views based on the new tracings. The dentary teeth were probably present, but not shown here.

Figure 5. Reconstruction of Sharovipteryx skull in several views based on the new tracings. The dentary teeth were probably present, but not shown here.

The new reconstruction of Sharovipteryx is similar to that of Cosesaurus and Longisquama, its phylogenetic sisters.

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
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Sharov AG 1971. New flying reptiles from the Mesozoic of Kazakhstan and Kirghizia. – Transactions of the Paleontological Institute, Akademia Nauk, USSR, Moscow, 130: 104–113 [in Russian].
wiki/Sharovipteryx

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