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As in the apes, the canines of the Hadar jaws were conical. In humans, the inner surface of the canine is flattened. In order to accommodate the projecting lower canine of A. afarensis, the upper jaw has a noticeable gap between the incisor and the canine. Other australopithecines also have the same gap. This gap, called a diastema, is also present in apes but not in humans.

Departures from the ape condition were minor. In an ape, the first premolar has a single cusp. In humans, the first premolar has a prominent second cusp. In all of the Hadar specimens except Lucy, the first premolar has a slightly developed second cusp (Johanson and Edey 1981, p. 270).

All in all, the apelike condition of the Hadar jaws is so pronounced that even Johanson admitted: “If David Pilbeam were to find any of them in Miocene deposits without any associated long bones, he would surely say it was an ape” (Johanson and Edey 1981, p. 376).

11.9.7.2 Postcranial Anatomy

Now we move on to the postcranial anatomy of A. afarensis, particularly Lucy. Several workers have found A. afarensis to be rather apelike, thus challenging Johanson’s view that Lucy was terrestrially bipedal in human fashion. Table 11.6 summarizes the evidence for arboreality in the postcranial anatomy of A. afarensis, and we shall amplify some of the points in this section.

Oxnard (1968) called attention to features of the Sterkfontein scapula suggesting that australopithecines probably engaged in holding the arms over the head in hanging behavior (Section 11.8.1, Table 11.5). A. afarensis has the same kind of scapula. Stern and Susman (1983, p. 284) concluded that the shoulder joint of A. afarensis was “directed far more cranially than is typical of modern humans and that this trait was an adaptation to use of the upper limb in elevated positions as would be common during climbing behavior.”

Johanson (1976, p. 808) had said that the Hadar hands bore “an uncanny resemblance to our own—in size, shape, and function.” But this appears to be incorrect.

Stern and Susman (1983, p. 284) concluded: “A summary of the morphologic and functional affinities of the Hadar hand fossils leads inexorably to an image of a suspensory adapted hand, surprisingly similar to hands found in the small end of the pygmy chimpanzee–common chimpanzee range.” M. W. Marzke (1983, p. 198), sharing this view, stated that the curved bones of the A. afarensis hand “recall the the bony apparatus which accommodates the well developed flexor musculature in living apes and positions it for efficient hooklike grip of the branches by the flexed fingers during arboreal climbing and feeding.”

So thus far we have in A. afarensis a gorillalike head, an upward-pointing shoulder joint indicating that the arm was used for suspensory behavior, and a hand with a powerful wrist and curved fingers, suitable for climbing. One can just imagine the effects of a painting or model of Lucy engaged in suspensory or other arboreal behavior. This would surely detract from her image as a creature well on the way to human status. Even if one believes Lucy could have evolved into a human being, one still has to admit that her anatomical features appear to have been misrepresented for propaganda purposes.

The distal humerus, the elbow region of the upper arm bone, fits the apelike pattern already established. Brigitte Senut, a physical anthropologist at the French Museum of Natural History, conducted a study of the outlines of cross sections of the distal humerus in living primates, including human beings, and fossil hominids. Senut (1981a, p. 282) discovered that the distal humerus of Lucy (AL 288-1M) was “pongid-like.” Pongids are the anthropoid apes, such as chimpanzees, gorillas, and orangutans. Senut (1981a, p. 282) concluded: “The scheme in the Afar specimen [Lucy] would suggest . . . its apelike pattern might be a result of a kind of suspension.”

Senut (1981a, p. 282) went on to say: “From our point of view, we would say that this specimen may be too pongid-like (i.e. specialized)