Xianglong zhaoi (Li et al. 2007) Yixian Formation, Early Cretaceous, 15.5 cm in length was originally considered an agamid lizard with elongated transverse processes and hyperelongated ribs, like the extant Draco volans. However Xianglong has a larger suite of traits shared with Kuehneosaurus and Icarosaurus. Not a lizard, Xianglong was a kuehneosaur that survived into the Cretaceous. That clade nests outside of the Lepidosauria in nearly all cladograms including the large reptile tree.
The skull was complete, but thoroughly crushed (Fig. 1).
The animated GIF (Fig. 1)
shows skull and mandible/hyoid elements on segregated layers using digital graphic segregation (DGS). Below (Fig.2) in the second half of any DGS process, those elements are reset to reproduce the skull in dorsal, palatal and lateral views.
is rather straightforward, moving elements back into their in vivo positions. Some elements seen edge-on, like the skull roof in lateral view, are either freehanded to the correct length and curved to fit, or reduced in one direction using the scaling tool of Photoshop. Note the great resemblance of this skull to that of a sister taxon, Kuehneosaurus (Fig. 4).
The skull of Xianglong
was originally traced with little regard to details (Fig. 3). DGS (Fig. 1) was able to pull those details out in a matter of hours from the published literature. Despite the large number of current detractors, DGS has value. This is just one of many such demonstrations.
Draco volans (Fig. 5) is an extant iguanian squamate lepidosaur with genuine elongate ribs framings its gliding membrane. Note the distinct skull shape. Also note the complete lack of elongate transverse processes on the dorsal vertebrae. Those elongate so-called transverse processes on kuehneosaurs are often, but not always the actual ribs, fused to the vertebrae (the proportion of rib to transverse process changes along each spinal column), as discussed earlier here in yet another heretical observation at odds with current paleontological conventions and paradigms.
Li P-P, Gao K-Q, Hou L-H and Xu X. 2007. A gliding lizard from the Early Cretaceous of China. PNAS 104(13): 5507-5509. doi: 10.1073/pnas.0609552104 online pdf