Müller and Garcia 2020 propose an alternate origin for Ornithischia

Müller and Garcia 2020 cast doubt
on all prior hypotheses of origin for the herbivorous dinosaur clade, Ornithischia.

From the abstract:
“Whereas ornithischian dinosaurs are well known from Jurassic and Cretaceous deposits, deciphering the origin and early evolution of the group remains one of the hardest challenges for paleontologists.”

No, it’s not. That problem was solved nine years ago. In the large reptile tree (LRT, 1729+ taxa; subset Fig. 1) Ornithischia + Sauropodomorpha arise from primitive phytodinosaurs like Eodromaeus, Barberenasuchus and Buriolestes. Tell Müller and Garcia to keep adding taxa. They have too few.

Figure 1. Subset of the LRT focusing on dinosaur and ornithischian origins.

Figure 1. Subset of the LRT focusing on dinosaur and ornithischian origins.

The cladogram in Müller and Garcia 2020
suffers from massive taxon exclusion. Incredibly, the basal ornithischians, Chilesaurus and Jeholosaurus (Figs. 1, 2) are not mentioned in the text. Surprising how anyone can discuss the origin of a clade without including its basalmost members?

To their credit, the authors do not mention pterosaurs.

To their discredit, the authors are still trying to push the invalidated relationship between the poposaur dino-mimic, Silesaurus, and the clade Ornithischia.

To their discredit, the authors omit all of the basal bipedal crocodylomorph sisters to Lagosuchus.

Due to taxon exclusion, the authors recover a traditional and invalid Saurischia / Ornithischia dichotomy. Add taxa to solve that problem.

A few reconstructions would have helped the authors identify several taxonomic mismatches.

Figure 1. Chilesaurus and kin, including Damonosaurus and basal phytodinosauria.

Figure 2. Chilesaurus and kin, including Damonosaurus and basal phytodinosauria, from 2015.

Figure 1. Skulls of Daemonosaurus, Haya and Jeholosaurus to scale.

Figure 3. Skulls of Daemonosaurus, Haya and Jeholosaurus to scale. Illustration from 2015.

You can access the Müller and Garcia 2020 paper
and get a free PDF here.


References
Müller RT and Garcia MS 2020. A paraphyletic ‘Silesauridae’ as an alternative hypothesis for the initial radiation of ornithischian dinosaurs. Biology Letters 16(8): 20200417. doi: 10.1098/rsbl.2020.0417 

wiki/Ornithischia

4 thoughts on “Müller and Garcia 2020 propose an alternate origin for Ornithischia

    • Taxon exclusion is usually the only problem, as I think it is here. No great insight otherwise. The taxon list has been online for several years. The .nex file will be going to Dr. Garcia shortly by request. A suggestion: just add the pertinent taxa using your own character list.

  1. Can you please send us a Nex file of the LRT?

    I’d like to see your scores on pertinent taxa and character states supporting the clades you have recovered.

    It just makes me curious to realize that you already solved this ‘problem’ nine years ago, and the solution was just sitting around here in the Internet, for free. I always find it interesting when someone thinks (in this case it must be true, right?) they have found a great solution to something and for some reason (who knows why?) the experts chose to ignore it, even though they were aware of this ‘great solution’. I mean, who doesn’t want to publish something as outstanding and revolutionary as this? Those scientists must be insane.

    I believe you already have Dr. Müller’s e-mail.

    Thanks in advance

    • No need for sarcasm. Just add pertinent taxa. The list is in this post. I am here to help. The .nex file is coming to you shortly, but the first step should be to add pertinent taxa to your own matrix. Let me know if anything interesting is recovered with your characters and scoring.

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