DGS – Digital Graphic Segregation helps reconstruct the Dauhugou lizard – again

Earlier we looked at the unnamed Daohugou lizard, IVPP V1347. Today there’s an update.

Figure 1. The skull of the Daohugou lizard IVPP V1347. At left, in situ. Middle as traced using DGS methods. At right, as figured by Evans and Wang 2005.

Figure 1. Click to enlarge. The skull of the Daohugou lizard IVPP V1347. At left, in situ. Middle as recently traced using DGS methods. At right, as figured by Evans and Wang 2005. Epipterygoids in yellow. Pterygoids in purple.

In phylogenetic analysis it nested as a sister to the basal tritosaur, Lacertulus, but the Daohugou lizard lived much later. The Daohugou lizard also nested with other Early Cretaceous tritosaur lizards, MeyasaurusHuehuecuetzpalli and Tijubina. These were difficult for professional paleontologists, like Evans and Wang (2005), to nest within the Iguania and Scleroglossa. That’s because they nest elswhere, in the Tritosauria!

Here the skull of the still unnamed Daohugou lizard is revised from an earlier reconstruction attempt. Here more details emerge with the mandible, naris, palatal and temporal regions. With these many minor modifications the phylogenetic nesting did not change.

Figure 2. The Daohugou lizard reconstucted. It's closest known relative is the basal tritosaur lepidosaur, Lacertulus.

Figure 2. The Daohugou lizard reconstucted. It’s closest known relative is the basal tritosaur lepidosaur, Lacertulus, but it phylogenetically leads to Huehuecuetzpalli.

Found and reconstructed in this round of DGS:
Epipterygoids, palate elements, a longer naris (shorter maxilla), more teeth below the orbit, lateral processes for the posterior frontal and anterior parietal, squamosal, anterior mandible elements, lacrimal.

In the lineage of pterosaurs
And because this Daohugou lizard nests within the Tritosauria, it is a sister to a similar-looking but currently unknown ancestor to pterosaurs that probably existed side-by-side with Lacertulus in the Late Permian.

References
Evans SE and Wang Y 2009. A long-limbed lizard from the Upper Jurassic/Lower Cretaceous of Daohugou, Ningcheng, Nei Mongol, China. Vertebrata PalAsiatica 47: 21–34.

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