A mouth full of different teeth

Heterodontosaurus is a funny little ornithischian. On the one hand it seems primitive as all get-out, but on the other hand there are people who persistently link them to marginocephalians (horned dinosaurs and dome-heads), and later taxa like Tianyulong really aren't clearing it up to anyone's satisfaction. I will say this, Heterodontosaurus has a bigger head and somewhat smaller abdomen than I was expecting.