Scelidosaurus nests next to Daemonosaurus as the most basal ornithischian in the large reptile tree. It’s obviously quite a bit more derived than Daemonosaurus with those plant-eating teeth and tiny antorbital fenestra (Fig. 1). Probably more bulky, too (Fig. 2). But no other taxon in the large reptile tree (338 taxa) is closer with the exceptions of Heterodontosaurus (Fig. 2) and Hexinlusaurus.
This is one of the dinosaurs I rescored a few weeks ago. I was under the impression that it had a longer rostrum. I’d like to see some papers on this.
A shorter skull gives Scelidosaurus something of a new look.
So, the origin of the Ornithischia remains in that gray unknown area represented by the unknown postcrania of Daemonosaurus. Scelidosaurus and Heterodontosaurus have the basic ornithischian pelvis. Pampadromaeus probably doesn’t since it is also basal to sauropods. Daemonosaurus is apparently where the magic transformation takes place in the pelvis.
Mike Hanson has kindly sent a less distorted side view skull. Here it is (Figure addendum). Thank you, Mike.This is to demonstrate that I make mistakes (this one more or less on purpose to encourage the reception of better data, see above) and that I correct them once revealed, as I have done before. Even with the distortion adjustment, the skull is still shorter and smaller in the rostrum than the data I had before. All I want is the best data. Again, thank you, Mike. Keep it coming.
Norman D 2001. Scelidosaurus, the earliest complete dinosaur in The Armored Dinosaurs, pp 3-24. Bloomington: Indiana University Press.
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 B, published online
Thulborn, RA 1977. Relationships of the lower Jurassic dinosaur Scelidosaurus harrisonii. Journal of Paleontology. 51: 725-739