On Wednesday, July 17, 2019, 9:21:35 AM CDT, David Marjanovic <david.marjanovic@gmx.at> wrote:
From the paper:
"Figured reconstructions in publications were considered to be indicative of the authorsâ determination of locomotor mode and of equal merit to textual determination. In instances where only diagrams were presented as the basis for determining the locomotor style, the reconstructed posture of the animal was considered to be indicative of the determination. In instances where both quadrupedal and bipedal diagrams were presented, taxa were determined to be facultative bipeds. We consider this to be justifiable because diagrams only come to exist in the literature as the consequence of a cascade of decisions: firstly, authors have made an intellectual assessment of an animal's posture based on their understanding of the osteological material that is available; secondly, that figure has been produced by the authors themselves or on the authors' behalf (and approved by them); thirdly, the peer-review process has deemed that figure appropriate for publication in a scientific journal. Therefore, the reconstruction must be considered representative of a reasonable scientific understanding of the animal at the time of publication. Taxa with no published locomotor mode were pruned from the dataset because the methods used in this study cannot accommodate unknown character states."
The optimism is unbelievable.
1) Reconstructions have to be in _some_ pose. When authors think the locomotor mode of their taxon _cannot_ be determined (or, say, would require serious work in biomechanics that may be beyond the scope of a descriptive or phylogenetic paper), they simply resort to the locomotor mode of a presumed close relative; to spell out the obvious, this should not be taken as evidence that any science has been done on the locomotor mode of the taxon in question.
2) Scientists, including whole teams of reviewers, have been known to disagree. Determinations of the locomotor modes of different taxa by different people are not necessarily comparable at all.
3) You'll be surprised to learn how little most reviewers care about figures. It's not as bad as with supplementary information, but still.
Now, the first and the third point only concern less than half of the paper, including the first two figures:
"To assess the sensitivity of our analytical approach, we replicated the following analyses using a dataset that excluded 15 taxa for which there was only diagrammatic data available."
This approach is used for the third and the fourth figure.
But in the first and the third figure alike, *Asilisaurus* is shown as quadrupedal, while *Silesaurus* is shown as facultatively bipedal, making *Silesaurus* represent a separate origin of facultative bipedality from original quadrupedality. Based on what? Sterling Nesbitt's gut feeling, but just for *Asilisaurus*, and Jerzy Dzik's gut feeling, but just for *Silesaurus*?
*Saturnalia* and *Efraasia* are shown as facultative bipeds in the second and the fourth figure. This should be considered disproved by the recent work on *Plateosaurus* which showed it wasn't able to walk quadrupedally; *Plateosaurus* is scored as an obligate biped, but the implications of the work that showed this were not understood.