Sinosauropteryx
"Sinosauropteryx" was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of .
Pachycephalosauria
Pachycephalosaurs were bipedal ornithischians characterized by their thickened skulls. They had a bulky torso with an expanded gut cavity and broad hips, short forelimbs, long legs, a short, thick neck, and a heavy tail. Large orbits and a large optic nerve point to pachycephalosaurs having good vision, and uncharacteristically large olfactory lobes indicate that they had a good sense of smell relative to other dinosaurs.They were fairly small dinosaurs, with most falling in the range of 2–3 meters (6.6-9.8 feet) in length and the largest, "Pachycephalosaurus wyomingensis," estimated to measure 4.5 meters (14.8 feet) long and weigh 450 kilograms (990 pounds). The characteristic skull of pachycephalosaurs is a result of the fusion and thickening of the frontals and parietals, accompanied by the closing of the supratemporal fenestra. In some species this takes the form of a raised dome; in others, the skull is flat or wedge-shaped. While the flat-headed pachycephalosaurs are traditionally regarded as distinct species or even families, they may represent juveniles of dome-headed adults. All display highly ornamented jugals, squamosals, and postorbitals in the form of blunt horns and nodes. Many species are only known from skull fragments, and a complete pachycephalosaur skeleton is yet to be found.