A third look at Daemonosaurus

Updated February 28, 2015 with a new skull for Daemonosaurus.

Daemonosaurus is an odd sort of dinosaur that we looked at earlier here and here. Huge teeth. Seems hyper-carnivorous. Apparently not so according to its phylogenetic nesting.

Earlier the large reptile tree nested Daemonosaurus at the base of the Ornithischia (more primitive than Scelidosaurus), not far from Pampadromaeus, Thecodontosaurus and Sacisaurus, among the other phytodinosaur clades. After learning about the palate of Heterodontosaurus, gaining new insights into Pantydraco and revising the scoring of several dinosaur taxa (thanks M. Mortimer), I traced another DGS illustration and created a new reconstruction.

Figure 2 Daemonosaurus skull in 4 views. The new reconstruction is narrower than previously with a new descending pterygoid flange and very few other refinements. The jaw is shorter. The dentary fang(s) appear to slip into that pmx/mx notch as in Heterodontosaurus. A small comb-like dentary tip appears to be a precursor for the predentary found in ornithischians. Gray areas are unknown.

Figure 1. Daemonosaurus skull in 3 views. The new reconstruction is narrower than previously with a new descending pterygoid flange and very few other refinements. The jaw is shorter. The dentary fang(s) appear to slip into that pmx/mx notch as in Heterodontosaurus.

See, I’m always ready to change and ready to learn.
And there’s still more to learn, I’m sure. Here are the new in situ images.

Figure 2. Daemonosaurus with bones colored here. The right side of the skull is flipped. Click to enlarge.

Figure 2. Daemonosaurus with bones colored here. The right side of the skull is flipped. Click to enlarge.

The intermediate length cervicals suggest Daemonosaurus had a neck, midway between that of a typical ornithischian and sauropodomorph.

Daemonosaurus has a high naris, like Herrerasaurus and Massospondylus. The narial depression drops first, then the naris follows on other taxa.

Daemonosaurus has a shorter rostrum than Herrerasaurus and shorter than Pampadromaeus, but not as short as the phytodinosaurs.

The descending quadrate and quadratojugal in Daemonosaurus are also found in Heterodontosaurus and others.

References
Sues H-D, Nesbitt SJ, Berman DS and Henrici AC 2011. A late-surviving basal theropod dinosaur from the latest Triassic of North America. Proceedings of the Royal Society Bpublished online 

wiki/Daemonosaurus

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