The rise of the ruling reptiles (Ezcurra and Butler 2018) fiasco

Taxon exclusion and lack of simple oversight
has once again produced a cladogram (Fig. 1) of untenable relationships. And it got published (Ezcurra and Butler 2018). So many taxa are missing… so many untested assumptions are present… so many ‘by default’ nestings… so many impossible sisters.

Figure 1. Ezcurra and Butler 2018 cladogram. Yellow areas applied here to actual archosauromorph taxa in the LRT.

Figure 1. Ezcurra and Butler 2018 cladogram. Yellow areas applied here to actual archosauromorph taxa in the LRT. White areas are lepidosauromorphs.

This paper basically repeats errors
from earlier works (Nesbitt 2011, Ezcurra 2016). 

The Archosauromorpha is defined as
taxa closer to archosaurs than to lepidosaurs. In the large reptile tree (LRT, 1236 taxa) 
that split follows the basalmost amniote/reptiles, Gephyrostegus and Silvanerpeton. The latter is from the Viséan (Early Carboniferous). A series of amphibian-like reptiles nest at the base of the new Archosauromorpha. This hypothesis of relationships is completely lost on Ezcurra and Butler due to taxon exclusion on a massive scale, following their traditional untested hypotheses of relationships.

When you add more relevant taxa
you will find that the white taxa in figure 1 nest on the lepidosauromorph branch of your greatly expanded tree, while the yellow taxa nest on the archosauromorph branch. And many taxa will fill the gaping morphological gaps present here.

And yes,
many clades, including the Lepidosauromorpha and the Archosauromorpha, recovered from the devastating Permo-Triassic mass extinction event. No argument there.

Ezcurra MD 2016.The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriformsPeerJ 4:e1778
Excurra MD and Butler RJ 2018.The rise of the ruling reptiles and ecosystem recovery from the Permo-Triassic mass extinction. Proceedings of the Royal Society B Biological Sciences. DOI: 10.1098/rspb.2018.0361
Nesbitt SJ 2011.
 The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352:1–292 DOI 10.1206/352.1.

2 thoughts on “The rise of the ruling reptiles (Ezcurra and Butler 2018) fiasco

  1. You mention the LRT and your (unpublished) results and own thoughts as if the authors were obligated to follow them. Remember that most of the paleontologists do not agree with your methods nor yours results, they do not have to even the obligation to mention the LRT. Thousands (not to say millions) of researchers worldwide do not agree with your statements. The way you write your posts, make it seem like you are the only one blessed with the truth. I know that you will say that one of the problems is simply taxa exclusion, but we both know that it is not going to make any difference if the authors add lepidosaurs to their analyses, once their characters are not those of LRT, thus they will not recover the same topologies. The taxa are not the same, the caracters are no the same, the methods are not the same and even the definitions of the used jargon is not the same. You are simply different tham the rest (and I respect that).

    • I’m not trying to be different, Mauricio. This is what happens when you add taxa to studies that lack relevant taxa. It’s that simple. Whenever relevant taxa are tested elsewhere (Diandongosuchus, Chilesaurus, etc.) results confirm the earlier LRT results. And by the way, by publishing online, I am publishing. Many others publish online, too. Peer-review is what I don’t have.

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