SVP 2017 abstracts: Does Malerisaurus nest with Azendohsaurus?

The short answer is

You might recall
we looked at Malerisaurus earlier.

A different take comes from the Nesbitt et al. 2017 SVP abstract:
“Mediation of some of these challenges is now possible with the recently recognized early
archosauromorph clade Allokotosauria. This clade contains disparate, ecologically
diverse (faunivores and herbivores), and typically larger bodied (1-3 meters in length)
archosauromorphs (Azendohsaurus, Trilophosaurus), but to this point, plesiomorphic,
early-diverging allokotosaurians have not been identified.

“Here, we recognize specimens assigned to the enigmatic taxon Malerisaurus from both present-day India and western Texas as members of Allokotosauria, and more specifically, the Azendohsauridae. The recognition of Malerisaurus as both an allokotosaur and an azendohsaurid has also helped identify other fragmentary remains of close relatives from Triassic deposits across Pangea including India, elsewhere in North America, and Africa. As such, Allokotosauria had a near Pangean distribution for much of the Middle to Late Triassic. Allokotosauria represents one of the oldest successful clades of archosauromorphs that achieved a wide geographic distribution and both taxonomic and ecomorphological diversity.”

The Protorosaurs, Malerisaurus, Prolacerta, Protorosaurus, Pamerlaria and Boreopricea.

Figure 1. Click to enlarge. The Protorosaurs, Malerisaurus, Prolacerta, Protorosaurus, Pamerlaria and Boreopricea. It is easy to see why these taxa become confused with Trilophosaurus and Azendohsaurus. More taxa solves the problem. 

In the
large reptile tree (LRT 1050 taxa) Malerisaurus nests with other protorosaurs within the new Archosauromorpha, sharing many traits by convergence with the Allokotosauria. This clade of currently three taxa (Trilophosaurus, Azendohsaurus and horned Shringasaurus) nests within the Rhynchocephalia between the derived taxa, Noteosuchus and Mesosuchus all within the new Lepidosauromorpha.

I’m guessing,
based on past performance (I was not in Calgary), that Nesbitt et al. did not add any or many basal rhynchocephalians to their cladogram, so this new odd nestings appears to join other odd nestings, likely victims of taxon exclusion.

Nesbitt SJ et al. (nine co-authors) 2017. The ‘strange reptiles’ of the Triassic. The morphology, ecology, and taxonomic diversity of the clade Allokotosauria illuminated by the discovery of an early diverging member. SVP abstracts 2017.

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