Weigeltisaurus skull reconstruction(s)

A new paper
by Bulanov and Sennikov (2015) reconstructs the holotype skull of Weigeltisaurus, a Permian gliding lepidosauriform (Fig. 1). We looked at this specimen earlier here guided by published drawings. Today we have a published photo of the specimen (see below). Previously Weigeltisaurus was considered a junior synonym of Coelurosauravus. Bulanov and Sennikov argue that Weigeltisaurus is a distinct genus.

Figure 1. Weigeltisaurus skull reconstructed by Bulanov and Sennikov (gray scale), and using DGS techniques (color). They did not attempt to trace the occiput, nor did they understand that the posterior crest is the supratemporal, displaced in situ and that the main portion is a very large squamosal that sweeps up. This skull is nearly identical to that of sister taxa, with the exception of the extended posterior elements, probably for secondary sexual selection. The same cannot be said of the Bulanov and Sennikov reconstruction which is, unfortunately, unique as is.

Figure 1. Weigeltisaurus skull reconstructed by Bulanov and Sennikov (gray scale), and using DGS techniques (color). They did not attempt to trace the occiput, nor did they understand that the posterior crest is the supratemporal, displaced in situ and that the main portion is a very large squamosal that sweeps up. This skull is nearly identical to that of sister taxa, with the exception of the extended posterior elements, probably for secondary sexual selection. The same cannot be said of the Bulanov and Sennikov reconstruction which is, unfortunately, unique as is.

Unfortunately
Bulanov and Sennikov made so many mistakes in their reconstruction that their arguments for retaining the genus Weigeltisaurus are difficult to support. Furthermore Bulanov and Sennikov do not reference sister taxa skulls to guide them through the process of reconstruction. Sister taxa include Jesairosaurus, Palaegama and Lanthanolania. Perhaps they do not know which taxa were sister taxa. The phylogenetic nesting of Coelurosauravus is typically not associated with kuehneosaurids and the taxa listed above. Finally, a phylogenetic analysis is missing.

The present interpretation 
differs from the Bulanov and Sennikov interpretation in several regards. They missed the occiput. I traced it. They did not include supratemporals. I interpret them here, displaced toward the jaw joint in situ. The saw a postorbital that was the exact mirror image of the postorbital process of the jugal. I interpret that as the other postorbital process of the jugal, flipped along with the frontals, which are exposed ventrally through the orbit. All of the bones are closely matched by sister taxa, like Jesairosaurus and differ largely and only in the secondary sexual character, the extension of the cranial frill.

If Bulanov and Sennikov
were going to separate Weigeltisaurus from Coelurosauravus they should have presented them both side by side.

By convergence
the cranial crest of Weigeltisaurus/Coelurosauravus is similar to that of the giant dinosaur, Styracosaurus and similar to that of helmeted chameleon Trioceros hoehnelii.

References
Bulanov VV and Sennikov AG 2015. Substantiation of validity of the Late Permian genus Weigeltisaurus Kuhn, 1939 (Reptilia, Weigeltisauridae) Paleontological Journal 49 (10):1101–1111.

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