Daemonosaurus, the Phytodinosauria and the Persistence of the Postfrontal

Earlier
we nested the Triassic saber-tooth, Daemonosaurus, at the base of the Ornithischia and near the base of the Phytodinosauria. The addition of the sauropodomorph, Leyesaurus (Apaldetti et al. 2014, Triassic/Jurassic boundary) to the large reptile tree supports that nesting with a very similar skull (Fig.1).

Figure 1. Click to enlarge. Sisters to Daemonosaurus, including Leyesaurus and Jeholosaurus. The postfrontal (in light red) is not fused in most of these taxa (Heterodontosaurus is the exception), contra current dinosaur paradigms. Note the resemblance of Daemonosaurus to the basal sauropodomorph, Leyesaurus. The increase in tooth size in Daemonosaurus was not derived from theropods, but was a unique character trait, shared, more or less with its sister, Jeholosaurus and to a lesser extent in Heterodontosaurus.

Figure 1. Click to enlarge. Sisters to Daemonosaurus, including Leyesaurus and Jeholosaurus. The postfrontal (in light red) is not fused in most of these taxa (Heterodontosaurus is the exception), contra current dinosaur paradigms. Note the resemblance of Daemonosaurus to the basal sauropodomorph, Leyesaurus. The increase in tooth size in Daemonosaurus was not derived from theropods, but was a unique character trait, shared, more or less with its sister, Jeholosaurus and to a lesser extent in Heterodontosaurus.

Along the way
it appeared that the postfrontal was retained in basal dinosaur taxa and outgroups, contra traditional dinosaur thinking.

Leyesaurus and Daemonosaurus
share greatly elongate cervicals and other traits (Fig. 1). Daemonosaurus was not included in the original analysis, but then Leyesaurus did not nest as a basal sauropodomorph as it does here. Leyesaurus has quite a wide skull, distinct from most basal dinosaurs. It nests with Massospondylus, which earlier we noted looked a lot like Daemonosaurus.

References
Apaldetti C, Marinez RN, Alcober OA and Pol D 2014. A New Basal Sauropodomorph (Dinosauria: Saurischia) from Quebrada del Barro Formation (Marayes-El Carrizal Basin), Northwestern Argentina. PLoS ONE 6(11): e26964. doi:10.1371/journal.pone.0026964

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