New paper on early dinosaur relationships suggests silesaurs could be basal ornithischians

[Sim]

Norman and Baron, two of the authours who revived Ornithoscelida, and some other authours have a new paper in which:

1. They acknowledge any of the competing hypotheses for early dinosaur evolution could be correct (Ornithischia-Saurischia, Ornithoscelida-Saurischia, Theropoda-Phytodinosauria) although their unconstrained analysis ends up supporting Ornithischia-Saurischia. 

2. They find support for silesaurs being basal ornithischians, in addition to silesaurs existing at the time when early ornithischians should have existed but had apparently not been found.  Also if silesaurs are ornithischians, they show how the beak in ornithischians appeared.

3. They find herrerasaurids to be saurischian dinosaurs that are neither theropods or sauropodomorphs.

4. Eoraptor is found to indeed be a sauropodomorph.

5. Chilesaurus is found to be a heterodontosaurid, so an ornithischian obviously.  However, they acknowledge unpublished new information supports it being a theropod.

Link to the paper: https://www.researchgate.net/publication/363196742_Taxonomic_palaeobiological_and_evolutionary_implications_of_a_phylogenetic_hypothesis_for_Ornithischia_Archosauria_Dinosauria

An easy to view render of the unconstrained analysis can be seen here, it's the second phylogenetic analysis shown: https://en.wikipedia.org/wiki/Silesauridae

[VD231991]

Müller and Garcia (2020) are actually the first authors to recover silesaurids as basal ornithischians, finding Silesauridae to be paraphyletic with respect to the ornithischian clade for which Dave Norman and colleagues employ the name Parapredentata in the 2022 paper you mention. Ferigolo and Langer (2007) argued that the silesaurid Sacisaurus had a predentary-like structure and therefore crucial to deciphering the origin of the ornithischian predentary, and Desojo et al. (2020) note that a handful of craniodental and postcranial characters of Pisanosaurus are shared with Jurassic-Cretaceous ornithischians despite recognizing that many postcranial characters of this taxon are widespread among early dinosauriforms, including most silesaurids, and thus the cladistic placement of Pisanosaurus as more closely related to ornithischians than to Sacisaurus or Silesaurus according to Müller and Garcia (2020) doesn't seem too problematic because the author's phylogenetic placement of Lewisuchus signals that the earliest ornithischians were omnivorous judging from the fact that Lewisuchus has recurved tooth crowns with finely serrated margins.

Although Norman et al. take note of unpublished data suggesting a theropod placement for Chilesaurus, the nature of the teeth of Chilesaurus raises questions about whether the problematic saurischian Eshanosaurus might be a Chilesaurus relative because even though Barrett (2009) finds Eshanosaurus to be distinct from 'prosauropods', Kirkland et al. (2005) note that the absence of a downturned mandibular symphysis in Falcarius unlike in Eshanosaurus further casts doubt on Eshanosaurus being a therizinosaur, and Chilesaurus has the downturned mandibular symphysis of Eshanosaurus. In other words, both Chilesaurus and Eshanosaurus could constitute a race of plant-eating saurischians distinct from basal sauropodomorphs and therizinosaurs (the assignment of Fukuivenator to Therizinosauria by Hattori et al. [2021] suggests that the most primitive therizinosaurs had an omnivorous dentition because Falcarius had a saurischian-type pelvis, as did Fukuivenator).

Barrett, P. M., 2009. The affinities of the enigmatic dinosaur Eshanosaurus deguchiianus from the Early Jurassic of Yunnan Province, People's Republic of China. Palaeontology. 52 (4): 681−688. doi:10.1111/j.1475-4983.2009.00887.x.

Desojo, J.B., Fiorelli, L.E., Ezcurra, M.D., Martinelli, A.G., Ramezani, J., Da Rosa, Á.A.S., Baczko, M.B. von, Trotteyn, M.J., Montefeltro, F.C., Ezpeleta, M., and Langer, M.C., 2020. The Late Triassic Ischigualasto Formation at Cerro Las Lajas (La Rioja, Argentina): fossil tetrapods, high-resolution chronostratigraphy, and faunal correlations. Scientific Reports 10: 1–34.

Ferigolo, J. and Langer, M.C., 2007. A Late Triassic dinosauriform from south Brazil and the origin of the ornithischian predentary bone. Historical Biology 19 (1): 1–11. doi:10.1080/08912960600845767.

Hattori, S., Kawabe, S., Imai, T., Shibata, M., Miyata, K., Xu, X., and Azuma, Y., 2021. Osteology of Fukuivenator paradoxus: a bizarre maniraptoran  theropod from the Early Cretaceous of Fukui, Japan. Memoir of the Fukui Prefectural Dinosaur Museum 20: 1–82.

Kirkland, J. I., Zanno, L. E., Sampson, S. D., Clark, J. M., and DeBlieux, D. D., 2005. A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah. Nature 435 (7038): 84–87. doi:10.1038/nature03468.

Müller, R.T. and Garcia, M.S., 2020. A paraphyletic 'Silesauridae' as an alternative hypothesis for the initial radiation of ornithischian dinosaurs. Biology Letters 16 (: 20200417. doi:10.1098/rsbl.2020.0417.

[Sim]

Oh, the connection between Eshanosaurus and Chilesaurus is interesting and I didn't know of it.  I was never convinced Esahnosaurus was a therizinosaurian.