Sharov’s Wing and a Message to My Readers

Holotype and only specimen of Sharovipteryx mirabilis (Sharov, 1971), photographed by Wikipedia user Ghedoghedo in Prague, Czech Republic, during the Dinosaurium exhibition in 2014.

Sharovipteryx mirabilis is one of those strange animals that entices much yet reveals little. A single specimen is known, presented a partial skeleton with impressions of bones and some skin. Bits of all parts are known, yet very little is easily discerned, and has confounded many.

While some might want to look deeper and closer using various lighting mechanisms such as UV exposure or chemical testing of material inclusions to determine whether bone, other organic tissue preservation is present and where. Yet others have taken to using photos not unlike the above photo, but at worse resolution, to describe whole swaths of “hidden” information. I would describe these methods but I will not waste my breath:

When you have to reduce the quality of your source material to invent “evidence” to fit a preconceived notion about the relationships of an animal, I think you’ve gone too far. I would say further than when you defend these methods in the face of increasing criticism, but claim you are doing science, you have a flawed definition of “science” wholly out of keeping with the definition and spirit of the word. Sadly, such efforts of low quality have been done, on this and many, many other non-dinosaurian tetrapod subjects, and rather than point you to an example, I decided as a countermeasure to contribute to more accurate efforts to depict some of these animals.

Thus, a skeletal reconstruction of Sharovipteryx mirabilis:

Sharovipteryx mirabilis (Sharov, 1971; originally named Podopteryx, was replaced with Sharovipteryx by Cowen in 1981). This skeletal reconstruction is released to the general public without restriction; thus, you are free to share it, modify it, share the modified version, slap it in memes, print it out, whatever. Whatever.

Some notes:

1. Almost the entirety of the shoulder girdle, forearm, pelvis, gastral basket, haemal arches are reconstructed after other archosauromorphs.
2. The only soft-tissue shown is the muscle, skin, body fat, and the large membranes between the toes and along the back of the leg.
3. Inference was taken from a recently described relative, Ozimek volans Dzik & Sulej, 2016. In that work, Sharovipteryx and Ozimek were inferred to be members of the peculiar group Tanystropheidae, which is undergoing substantial revision at the moment. Unlike Ozimek, Sharovipteryx has a longer, strap like scapula.
4. Because the specimen is preserved exposed from above, a side view has to be extrapolated. The largest error I can foresee is the side view of the skull, which hasn’t been reconstructed as closely after Ozimek.

Reconstruction of Ozimek volans Dzik & Sulej, 2016, reassembled from CT-extracted bones.

This animal is depicted in the act of leaping. A recent study of Scleromochlus taylori by Bennett (2020) found evidence the small Elgin archosauriform consistent with leaping, due in part to disparity in hindlimb to forelimb length. However, rather than infer based solely on this, I simply show this leaping rather than as a “hopper” as Bennett inferred for Scleromochlus, which I don’t otherwise discuss here. Work by Dyke et al. (2006) and implied for some time indicated the legs and their membranes formed a functional and effective aerofoil and would have allowed Sharovipteryx to be a reasonable glider. Thus, here Sharovipteryx is leaping, perhaps from a tree, to create momentum for a long glide.

References

1. Sharov, A. G. 1971. New flying reptiles from the Mesozoic of Kazakhstan and Kirghizia. [Transactions of the Paleontological Institute] 130: 104-113. [in Russian]
2. Cowen, R. 1981. “Homonyms of Podopteryx“. Journal of Paleontology. 55 (2): 483.
3. Dyke, G. J., Nudds, R. L. & Rayner, J. M. V. 2006. Flight of Sharovipteryx mirabilis: the world’s first delta-winged glider. Journal of Evolutionary Biology. 19 (4): 1040-1043.
4. Dzik, J. & Sulej, T. 2016. An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages. Acta Palaeontologica Polonica 61 (4): 805-823.
5. Bennett, S. C. 2020. Reassessment of the Triassic archosauriform Scleromochlus taylori: neither runner nor biped, but hopper. PeerJ 8: e8418.