Forbidden Archeology: The Hidden History of the Human Race

Almost 20 years earlier, Sir Arthur Keith (1935, p. 163) wrote: “the chin of this representative of early humanity was the seat of a bony tumour of an exceedingly rare kind. The tumour, which grew from the deep aspect of the jaw, just behind the chin, has spread over and obscured the normal features of this region. Enough remains, however, to make quite certain that in dimensions and in its features, the chin region of this early being was shaped as in primitive types of living humanity—such as the aborigines of Australia.” In other words, Keith, at that time, took the chin features to be within the range of anatomically modern humans, Homo sapiens sapiens.

Despite the effects of the bone tumor on the inner surface of the chin, Tobias (1962, p. 349) thought the lower front part of the Kanam jaw had some features like that of the modern human chin—although not as well developed. For example, the Kanam jaw, like the human jaw, has a pronounced incurvation below the level of the teeth and an outward swelling of the bone at the base of the front part of the jaw (Figures 11.4g–h).

But Tobias also called attention to the depth and thickness of the jaw, the relatively large size of some of the teeth, and other features that he regarded as primitive. Tobias (1962, p. 355) observed: “Several, though not all, of these features might be encountered individually as exceptional variants among modern African mandibles.” He thought the Kanam jaw most closely resembled the late Middle Pleistocene mandible from Rabat in Morocco, and Upper Pleistocene mandibles such as those from the Cave of Hearths in South Africa and Dire-Dawa in Ethiopia (Tobias 1968, p. 181).

Recent workers class Rabat and Cave of Hearths as “early archaic Homo sapiens” (Bräuer 1984, pp. 380, 394). The Rabat mandible is said to have no true chin (Howell 1978, pp. 196, 204), while the Cave of Hearths mandible is said to have “a slight to moderate chin” (Tobias 1971, p. 338). The Dire-Dawa mandible, said to have no true chin, is nevertheless listed as Homo sapiens sapiens (Howell 1978, p. 214).

According to Tobias (1968, pp. 190–191), all of these mandibles displayed “neanderthaloid” features. He placed them, along with other neanderthaloid fossils, in the subspecies Homo sapiens rhodesiensis, which he regarded as transitional between Homo erectus and more developed African Neanderthals.

In 1960, Louis Leakey (1960d, p. xix), retreating from his earlier view that the Kanam jaw was sapiens-like, wrote: “it becomes highly probable that the Kanam mandible represents, in fact, a female of Zinjanthropus.”

Leakey had found Zinjanthropus in 1959, at Olduvai Gorge (Section 11.4.1). He briefly promoted this apelike creature as the first toolmaker, and thus the first truly humanlike being. Shortly thereafter, fossils of Homo habilis were found at Olduvai. Leakey quickly demoted Zinjanthropus from his status as toolmaker, placing him among the robust australopithecines (A. boisei ).

In the early 1970s, Leakey’s son Richard, working at Lake Turkana, Kenya, discovered fossil jaws of Homo habilis that resembled the Kanam jaw. Since the Lake Turkana Homo habilis jaws were discovered with a fauna similar to that at Kanam, the elder Leakey changed his mind once more, suggesting that the Kanam jaw could be assigned to Homo habilis (L. Leakey 1972, p. 36; Cole 1975, p. 362).

That scientists have attributed the Kanam jaw to almost every known hominid (Australopithecus, Australopithecus boisei, Homo habilis, Neanderthal man, Early Homo sapiens, anatomically modern Homo sapiens) shows the difficulties involved in properly classifying hominid fossil remains.

Tobias’s suggestion that the Kanam jaw came from a variety of early Homo sapiens, with neanderthaloid features, has won wide acceptance. Yet as can be seen in Figure 11.4, which shows outlines of the Kanam mandible and other hominid mandibles, the contour of the Kanam mandible’s chin region is similar to that of the Border Cave specimen (f ), recognized as Homo sapiens sapiens, and to that of a modern South African native (g). All three share two key features of the modern human chin, namely, an incurvation toward the top and a swelling outward at the base.