Lanthanosuchus part 2: Guessing the Post-Crania

Revised again July 13, 2014 by deleting references to Sclerosaurus and adding references to Emeroleter and Romeriscus. 

Addendum 2/14/2012:
Adding taxa has shifted understanding of Lanthanosuchus and its post-crania. Now Macroleter, Emeroleter and Romeriscus are the closest known sister taxon.

Macroleter, the closest known sister to Lanthanosuchus

Addendum figure 1. Macroleter, nesting at the base of the clade that produced Lanthanosuchus, demonstrating a plesiomorphic post-cranial morphology.

Figure 2. Emeroleter nests between Macroleter and Romeriscus + Lanthanosuchus.

Figure 2. Emeroleter nests between Macroleter and Romeriscus + Lanthanosuchus. Note the lateral temporal fenestra.

Figure 3. Romeriscus, the flattened sister to Lanthanosuchus.

Figure 3. Romeriscus, the flattened sister to Lanthanosuchus had flat, frog-like ribs and long, strong legs.

The skull of Lanthanosuchus in several views and colorized.

Figure 4. The skull of Lanthanosuchus in several views and colorized. Wonder what the post-crania looks like? See figures 1-3 for clues.

Not Much Past the Skull is Known
We just looked at the weird flat-skullled, Permian taxon, Lanthanosuchus and learned that it was a key taxon linking the big Permian diadectomorphs to the small lizardy lepidosauriforms. Unfortunately very little is known of the post-crania of Lanthanosuchus. In such cases, we look to predecessor and successor sister taxa in order to make a best guess as to what the missing parts might look like.

We Learn About the Unknown from the Known
As weird as Lanthanosuchus was, currently there are no closer sister taxa than Romeriscus, Emeroleter and Macroleter. So they are our best guess/model to illustrate the unknown post-crania of Lanthanosuchus. The body was likely wide and flat, like the skull. The hands and feet would have been nearly the same size as each other, with relatively short toes, but retaining the primitive phalangeal formula of 23454.

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
Sues H-D and Reisz RR 2008. Anatomy and Phylogenetic Relationships of Sclerosaurus armatus (Amniota: Parareptilia) from the Buntsandstein (Triassic) of Europe. Journal of Vertebrate Paleontology 28(4):1031-1042. doi: 10.1671/0272-4634-28.4.1031 online

wiki/Lanthanosuchus

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