The Skull of Sharovipteryx

Apart from the hands of Sharovipteryx, the skull (Fig. 1) has given workers (including yours truly) much trouble. Although complete and largely articulated, the skull was crushed and invaded by a wasp-like, ant-like insect. My mistake (Peters 2000) was considering the large split posterior bones to be between the pterygoids, which they resemble. However, when reassembled in three-dimensions, the split disappears as the dome-like frontals and parietals come together at the midline. Not all the bones are bone-colored. Some remain wrapped in scaly skin.

DGS
I used DGS (digital graphic segregation) to identify the bones. If someone else wants to re-identify the skull bones of Sharovipteryx, please report any and all confirmations and discrepancies.

sharovipteryx-skull588

Figure 1. The skull of Sharovipteryx in situ (right) and traced left). Note the details visible in the scalation of the snout and the wrinkles (or are those pycnofibers?) of the neck, along with the breadth of the neck skin relative to the narrow cervicals. This image supersedes an earlier one.

Reconstructed Skull
Copying and pasting the skull elements recovers a skull midway between those of Cosesaurus and Longisquama + basal pterosaurs (Fig. 2). The naris was enlarged and largely posterior to the tooth-bearing portion of the premaxilla. The ascending process of the premaxilla extended to the anterior orbit. The maxilla included two longer teeth ventral to the ascending process while some of the posterior teeth were multi-cusped. The narrow snout and wide cranium afforded some degree of binocular vision. The orbit was the largest skull opening, twice the size of the antorbital fenestra (without a fossa). The naris was also larger slightly than the antorbital fenestra. The skull was domed. The dorsal rim of the postorbital was in line with the orbit dorsal rim. The palate was relatively gracile with a robust anterior pterygoid. The palatine and ectopterygoid were in contact with one another, prior to their fusion in pterosaurs to form the L-shaped ectopalatine. The dentary included procumbent anterior fangs and posterior multi-cusped teeth.

Figure 2. Sharovipteryx mirabilis in various views. No pycnofibers added yet. Click to learn more.

Figure 2. Sharovipteryx mirabilis in various views. No pycnofibers added yet. Click to learn more.

Phylogenetic Results
Despite its unique body, the reconstructed skull of Sharovipteryx offers few surprises or unexpected adornments. It appears to be a standard primitive fenestrasaur skull, a little longer than in Cosesaurus with teeth more like those of basal pterosaurs and Longisquama.

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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4 thoughts on “The Skull of Sharovipteryx

  1. The insect as outlined looks to be a beetle — which would make better sense than a wasp… beetles are dominant in late-stage, dry carrion today (check any road-kill at mid-summer), and probably have been so since the Permian.

    By the way, what is the scale?

      • There’s a general habitus resemblance to the typical carrion beetles [Silphidae, especially the genus Nicrophorus. However, these are rather flattened, not cyclindrical. But it could be some entirely unrelated lineage. IF the outline is correct, we can see head, prothorax and elytra [front wings forming "shell"]
        You might also see darkling beetles [Tenebrionidae] which may have this general shape. They are not generally carrion specialists but typically feed on decaying material… But I emphasise that “beetle” is just a good guess without better detail, especially antenna shape.

        It is very unlikely to be higher Hymenoptera [wasps, ants], which have narrow waistsm, and would usually fragment before fossilisation — additionally these groups largely radiated in the Cretaceous, while beetles were already diverse in the Permian.

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