Forbidden Archeology_ The Full Unabridged Edition - Michael A. Cremo [506]
Measurements of several features of the lower (distal) end of the AL 333-4 First Family femur showed it to be outside the human range and within the ranges of chimpanzees, gibbons, and several species of monkeys. In fact “the distal end of the AL 333-4 femur actually appears less human-like than that of a woolly monkey” (Stern and Susman 1983, p. 297).
Christine Tardieu, an anthropologist at the Museum of Natural History in Paris, gave a slightly different assessment of the AL 333-4 distal femur, finding it barely within the modern human range, at “the extreme end closest to the apes” (Stern and Susman 1983, p. 299). Thus, as often happens, we find ourselves confronted with contradictory interpretations of the same fossil material, but on the whole, the femurs in question appear to be apelike.
Tardieu, in addition to measuring the AL 333-4 femur of the First Family group, also conducted studies of the distal femur of Lucy. She gave special attention to the notch in the femur that holds the upper end of the tibia, the larger of the two bones of the lower leg. In humans, the spine of the tibia fits tightly into the notch of the femur. In apes, the fit is looser. In this regard, Lucy is in the range of the gibbon. Tardieu (1981, p. 76) stated: “The loose fit of the articular surfaces . . . and the consequent laxity of the knee joint signify that the leg and the foot can be placed on the substrate in a much freer fashion than in Man.” This would be good for climbing, but unsatisfactory for extensive walking on the ground.
Commenting on Tardieu’s study of Lucy’s knee, Oxnard (1984, p. 334-ii) said she was led to “conclude that . . . its locking mechanism was not developed, implying that full extension of the leg in walking, a key point of human bipedality, was lacking.” Such features “suggested to Tardieu that ‘Lucy’ spent a considerable period of time climbing in the trees” (Oxnard 1984, p. 334-ii).
One can just imagine Lucy, hanging lazily from a tree limb by one of her arms, bending a small, dangling foot back from the ankle, while rotating her lower leg from the knee to bring the backward reaching foot in contact with a nearby limb.
The knee of Lucy (AL 288), like the original Hadar knee complex (AL 129), had a significant degree of valgus. Johanson, Lovejoy, and others held this to be an indication of humanlike posture and terrestrial bipedal gait. But, as we have seen, the orangutan and spider monkey have similar valgus angles, and they are arboreal.
In our anatomical survey, we have now progessed to the controversial feet of A. afarensis. Even Johanson had a difficult time disguising the manifestly apelike condition of Lucy’s foot. He wrote: “The afarensis phalanges are arched, and proportionally a good deal longer than those in modern feet. They might almost be mistaken for finger bones” (Johanson and Edey 1981, p. 345). Johanson also noted that the A. afarensis foot had “very large muscles whose presence is betrayed by markings along the sides of the phalanges” (Johanson and Edey 1981, p. 345). Such muscles would have been useful in hindlimb grasping.
It is amazing that Johanson could so candidly acknowledge the very apelike morphology of the afarensis foot and yet refuse to draw the obvious conclusion that it was used in arboreal behavior. Instead, Johanson stated: “Although similarly curved phalanges and muscle markings are found in the chimpanzee — reflecting the chimp’s ability to climb trees—Latimer warns that this does not mean that afarensis was a tree climber too” (Johanson and Edey 1981, p. 346 ). Bruce Latimer was one of Johanson’s graduate students and worked with him quite closely in Ethiopia on the Hadar finds, so his impartiality is suspect. He was later employed by Johanson to help with the reconstruction of A. afarensis. It is not unexpected that Latimer would agree with his professor, mentor, and employer that afarensis was a fully terrestrial