Spiny and Angry

Basal ornithischians were generally small, often covered in spiny dinofuzz, and not at all happy about it.

Archaeoceratops, Heterodontosaurus and Hypsilophodon, all covered in a mix of scales and quill-like dinofuzz based on preserved evidence in Kulindadromeus, Tianyulong and Psittacosaurus. Being small herbivores and/or omnivores in the Mesozoic, these animals probably needed both the porcupine-quills and a nasty attitude to survive.