A simple diagram demonstrating the differences in Saurischian and Ornithischian hips. A.Eoraptor, an early Saurischian; note the forward-pointing pubis B.Lesothosaurus, a primitive Ornithischian; note the reversed pubis C. Staurikosaurus (Saurischian) pelvis D.Lesothosaurus pelvis
Based upon the skeletal reconstruction available online. [link]
The protofeathers have been added assuming that the integumentary structures found in ornithischians are homologous to that of saurischians, making “feathers” a synapomorphy of the clade “Dinosauria”, if not Ornithodira (assuming the structures of pterosaurs are homologous too).
This was entirely made on Adobe Photoshop CS4, in order to try an experiment: to see if I was capable of drawing a “close enough” dinosaur only by digital means.
It has proven to be a quick way to draw, though I still prefer the results of combining freehand pencil drawing and coloring in Photoshop.