Pritchard, Sues, Reisz and Scott 2020
promise to bring us a look at the ‘osteology and phylogenetic affinities of the early gliding reptile Weigeltisaurus jaekeli” (Fig. 1).
no phylogenetic analysis, or any hint thereof, is to be found in the abstract.
We looked at Weigeltisaurus earlier
here when the skull (Fig. 1) was described by Bulanov and Sennikov 2015.
Weigeltisaurus is a relative of Coelurosauravus
(Fig. 2) and other pseudo-rib gliders. The ribs are dermal in nature, extending from the tips of the dorsal and lumbar ribs, whether few or many.
From the Pritchard et al. 2020 abstract:
“Weigeltisauridae is a clade of small-bodied Permian diapsids that represent the oldest known vertebrates with skeletal features for gliding. It is characterized by a cranium with a posterior bony casque, prominent horns on the temporal arches, and a series of elongate bony spars projecting from the ventrolateral surface on both sides of the trunk. Definitive specimens are known from upper Permian of Germany, Russia, and Madagascar, but the quality of their preservation previously limited understanding of the skeletal structure and phylogenetic affinities of these reptiles.”
All you have to do is add taxa (= minimize taxon exclusion) and let the software determine where these Permian pseudo-rib gliding lepidosauriforms nest. In the large reptile tree (LRT, 1752+ taxa; subset Fig. 3) these arboreal gliders nest at the base of the lepidosauriformes. (The Diapsida is now limited to just archosauromorphs with a diapsid-skull morphology, by convergence with lepidosauriformes). Only here, in the LRT, among all prior pertinent cladograms, is the clade of pseudo-rib gliders surrounded by arboreal taxa with weigeltosaurs nesting with kuehneosaurs. Usually they nest apart and too often close to marine taxa.
The Pritchard, Sues, Reisz and Scott abstract continues:
“Here, we present a revised account based on a nearly complete skeleton of Weigeltisaurus jaekeli from the Kupferschiefer of central Germany and a revised phylogenetic analysis of early Diapsida and early Sauria.”
That analysis must have been part of the oral presentation. There is no hint of it here. Sauria is an invalid clade. Diaspsida is restricted to the Archosauromorpha in the LRT.
“The specimen preserves all elements of the skeleton, save for the braincase, palate, some dorsal vertebrae, the carpus, and the tarsus. The well-preserved teeth in the maxilla are not conical but leaf-shaped, resembling those in the middle portion of the maxillae of the Russian weigeltisaurid Rautiania. The parietals bear rows of dorsolaterally oriented horns similar to those on the squamosals. The quadrate is a dorsoventrally short element with a tapering dorsal margin that lacks a cephalic condyle. The squamosal appears to cover the quadrate both laterally and posterodorsally. The manual and pedal phalanges are elongate and slender, similar to those of extant arboreal squamates. The unguals have very prominent flexor tubercles. A patagium was supported by elongate, slender bony rods. They are situated superficial to the preserved dorsal ribs and gastralia, corroborating the hypothesis that these structures represent dermal ossifications independent of and greater in number than the bones of the dorsal axial skeleton.”
Excellent description. But that was provided earlier (Bulanov and Sennikov 2015).
I guess we’ll have to wait for the paper.
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.
Pritchard A, Sues HD, Reisz R and Scott D 2020. Osteology and phylogenetic affinities of the early gliding reptile Weigeltisaurus jaekeli. SVP abstracts.
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