of the scapulocoracoid. In its general form, the forelimbs of Protoceratops were shorted than the hindlimbs, and composed by the humerus, radius, and ulna. The (upper arm bone) was large and slender, and at the lower part it meet with both radius and ulna. The had a slightly recurved shape and was longer than the ulna. A concavity was present on its upper part, serving as the connection with the humerus and forming the elbow. The was a rather short bone with a straight shape. The manus (hand) of Protoceratops had five digits (fingers). The first three fingers had unguals (claw bones) and were the largest digits. The last two were devoid of unguals and had a small size, mostly vestigial (retained, but without important function). Both hand and feet unguals were flat, blunt and hoof-like. The pelvic girdle was formed by the , , and . The ilium was a large element, having a narrow preacetabular process (anterior end) and a wide postacetabular process (posterior end). The pubis was the smallest element of the pelvic girdle and it had an irregular shape, although its lower end was developed into a pointed bony projection downwards. The ischium was the longest bone of the pelvic girdle. It had an elongated shaft with a somewhat wide lower end. The hindlimbs of Protoceratops were rather long, with a slighter longer tibia (lower leg bone) than femur (thigh bone). The (thighbone) was robust and had a rather rounded and pronounced greater trochanter, which was slightly recurved into the inner sides. The (shinbone) was long and slender with a wide lower end. On its upper region a concavity was developed for the joint with the smaller . The pes (foot) were composed of four and four toes which bore shovel-like pedal unguals. The first metatarsal and toe were the smallest, while the other elements were of similar shape and length. Classification Protoceratops was in 1923 placed within the newly named family Protoceratopsidae as the representative species by Granger and Gregory. This family was characterized by their overall primitive morphology in comparison to the more derived Ceratopsidae, such as lack of well-developed horn cores and relative smaller body size. Protoceratops itself was considered by the authors to be somehow related to ankylosaurians based on skull traits, with a more intensified degree to Triceratops and relatives. Gregory and Charles C. Mook in 1925 upon a more deeper