The posture of the great ape hand in locomotion, and its phylogenetic implications

✍ Scribed by William L. Straus Jr.

• Publisher: John Wiley and Sons
• Year: 1940
• Tongue: English
• Weight: 492 KB
• Volume: 27
• Category: Article
• ISSN: 0002-9483
• DOI: 10.1002/ajpa.1330270223

✦ Synopsis

FIGUBE

I t is a well-known and easily observed fact that the three great apes-chimpanzee, gorilla, orang-utan-when walking in quadrupedal fashion, never place the palms of their hands upon the ground. Instead, the last two joints of the second to fifth fingers are flexed, so that the animal typically rests upon the middle phalanges, with basal phalanges, metacarpus and carpus practically in a line with the forearm (fig. , below). That this differs fundamentally from conditions in other primates, is obvious, but the reasons for this peculiar posture, and its significance, are but little appreciated.

I have studied this phenomenon in the chimpanzee, following its ontogeny and examining certain of the underlying anatomical features.