Paradolichopithecus

Paradolichopithecus was a terrestrial monkey generally believed to have developed a large body size as a response to predator pressure, estimated to be similar in weight to the mandrill (~31 kg). Despite its close relation to macaques, it also shared a number of postcranial features with baboons. Its ankle joints also show a remarkable similarity with that of the hominid Australopithecus, and it has led to the idea that Paradolichopithecus may frequently have moved in a bipedal stance. The limbs of this genus were robust with prominent areas of muscular attachment, notably found on the humerus which had a length of 22.5 cm. The radius of this specimen was longer than the humerus as seen in the mandrill, measuring 25.2 cm, although it was also broader in structure than current mandrills and baboons.[4]

A fossil of this primate shows the talus bone having features much more alike australopithecines than modern baboons or chimpanzees, such as shape and placement, although some features are similar to bipedally trained Japanese macaques. The distal tibia found also has a distinctly more massive and square malleolus, differing from macaques or baboons and again showing a similarity to hominins. The morphology and width of the tibia shows that this primate had specific weight-bearing adaptations for terrestrial locomotion. The proximal humerus found in this site has a deep and wide attachment groove for the biceps along with a larger articulation area on the head, which relates to the increased mobility possible for the elbow joint found.[5]