Better resolution reveals more in ?L. rossii (Renestosaurus)

Updated with a new reconstruction July 2, 2014.

Earlier I worked with a low resolution black and white image of MFSN 19235 published in Renesto (1992), who questioned the affinity of Langobardisaurus? rossii (Bizzarini and Muscio 1995). Since this specimen definitely does not belong to Langobardisaurus, I suggested the generic name, Renestosaurus. Now, with better imagery, courtesy of Dr. Renesto, more precise details can be gleaned.

Figure 1. Click to enlarge. Better resolution image of Renestosaurus (above). Color tracings of elements (below). Recontructed pes, manus, pelvis and pectoral girdle (on white).

Figure 1. Click to enlarge. Better resolution image of Renestosaurus (above). Color tracings of elements (below). Recontructed pes, manus, pelvis and pectoral girdle (on white).

To all appearances the pelvis is missing. Actually one side had drifted to the posterior dorsals. The other drifted caudally. Both are small. The right foot is disarticulated and reconstructed here. It is smaller than the manus. The left tarsals are between the right femur and right crus. Some left toe bones are nearby on top of the proximal right crus. What Renesto considered a pelvis is the left femur. The left forelimb is largely disarticulated beneath the dorsal ribs. The complete pectoral girdle is visible.

 

Figure 2. Langobardisaurus(?) rossii (MFSN 19235) reconstructed. Here it nests between basal sphenodontids and basal tritosaurs + squamates.

Figure 2. Langobardisaurus(?) rossii (MFSN 19235) reconstructed. Here it nests between basal sphenodontids and basal tritosaurs + squamates.

A digger?
The robust proximal humerus and large manus hint at a digging niche. Too bad the skull is unknown.

Phylogenetic nesting
Despite the changes in a few scores, Renestosaurus continues to nest as it had before, with Homoeosaurus and Dalinghosaurus in a clade of pre-squamates derived from a sister to Gephyrosaurus. This clade was unknown prior to it recovery in the large reptile tree.

DGS
This is yet another example of DGS (Digital Graphic Segregation) helping to uncover details in a crushed fossil specimen. Higher resolution always helps, but if low resolution is all that is available, well, then that’s what we work with. In any case, more details were uncovered here using a photograph than were revealed from first-hand observation. I’m not bragging. I’m just suggesting other paleontologists should use this tool too.

And the use of the large reptile tree helped eliminate all other possible nesting opportunities from this list of several hundred taxa.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Bizzarini F and Muscio G 1995. Un nuovo rettile (Reptilia, Prolacertiformes) del Norico di Preone (Udine, Italia Nordorientale). Nota Prelimininare. Gortania – Atti Mus. Friulli. Sti. Nat., 16 (1994): 67-76, Udine.
Bizzarini F, Muscio G and Rossi IA 1995. Un nuovo rettile fossile Langobardisaurus? rossiin. sp. Prolacertiformes (Reptilia) della val Preone (UD), Prealpi Carniche Italine. 1-35 Grafiche Tipo, Catelgomberto.
Renesto S and Dalla Vecchia F 2007. A revision of Langobardisaurus rossii Bizzarini and Muscio, 1995, from the Late Triassic of Friuli (Italy)*

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