New origin of dinosaurs video by Dr. Sterling Nesbitt

There’s a new YouTube video
featuring Dr. Sterling Nesbitt describe his version of dinosaur origins.

Unfortunately
Dr. Nesbitt ‘pulls a Larry Martin‘ by concentrating on key dinosaurian traits and not concentrating on the last common ancestor (Fig. 2) in a wide gamut phylogenetic analysis, like the large reptile tree (LRT, 1515 taxa, subset Fig. 3). Nesbitt is great at finding bones in the field, and describing new taxa, but Nesbitt 2011 and Nesbitt 2017 omitted key proximal outgroups to the Dinosauria (Figs. 2, 3) and so he keeps missing ‘the big picture.’

Continuing an invalid tradition
Dr. Nesbitt nests the tropidosuchid proterochampsid, Lagerpeton, as a close dinosaur outgroup. He also nests pterosaurs close to the base of the Dinosauria, which has been a big mistake for nearly 20 years. Dr. Nesbitt omits bipedal crocodylomorphs (Figs. 2, 3) from his dinosaur cladograms, another traditional academic mistake.

Nesbitt’s taxon exclusion issues
are repaired in the LRT (subset Fig. 3) where the last common ancestor of every included taxon back to Silurian fish is documented and validated by minimizing taxon exclusion.

Figure 2. The origin of dinosaurs to scale. Gray arrows show the direction of evolution. This image includes Decuriasuchus, Turfanosuchus, Gracilisuchus, Lewisuchus, Pseudhesperosuchus, Trialestes, Herrerasaurus, Tawa and Eoraptor.

Figure 2. The origin of dinosaurs to scale in the LRT. Gray arrows show the direction of evolution. This image includes Decuriasuchus, Turfanosuchus, Gracilisuchus, Lewisuchus, Pseudhesperosuchus, Trialestes, Herrerasaurus, Tawa and Eoraptor.

Figure 1. Revision to the LRT with a focus on the Archosauria. Here taxa with a long carpus all nest within the Crocodylomorpha, following traditional thinking. Dinosaur outgroups are reduced. PVL 4597 is still the basalmost archosaur.

Figure 1. Revision to the LRT with a focus on the Archosauria. Here taxa with a long carpus all nest within the Crocodylomorpha, following traditional thinking. Dinosaur outgroups are reduced. PVL 4597 is still the basalmost archosaur.


References
Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bull. Am. Mus. Nat. Hist. 352, 1–292.
Nesbitt et al. 2017. The earliest bird-line archosaurs and the assembly of the dinosaur body plan. Nature (online here).

https://pterosaurheresies.wordpress.com/2017/04/13/teleocrater-a-sister-to-yarasuchus-not-the-earliest-bird-line-archosaur/

https://pterosaurheresies.wordpress.com/2018/02/22/redefining-what-makes-a-dinosaur/

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