Which animal forelimb does the human arm most closely resemb

Which animal forelimb does the human arm most closely resemble? Hypothesize why the human more closely resembles your chosen animal.

Solution

The human arm resembles that of the reptiles. The pectoral girdle is typically reptilian with large precoracoids, coracoids and interclavicle. And among the various groups of reptiles the Therapsid reptiles included in the group Synapsida, may be considered as ancestors. Monotremes in mammals have the characteristics of both reptiles and mammals.