[16] The red panda likely originally evolved the "pseudo-thumb" in order to assist in arboreal locomotion.

[22] Recently, the enlarged radial sesamoid bone of cotton rats has been studied.

[23] Their enlarged radial sesamoid bone and that of the giant panda have a similar morphology and size relative to the rest of the hand.

[23] The reason for this evolutionary change is still unknown; however, it may be to assist in grasping small objects and thin branches.

[23] Elephants have similarly enlarged sesamoid bones in both their forelimbs and hindlimbs, referred to as the prepollex and prehallux, respectively.