Michael Balter asks a question I’ve hit here a few times: “What ever happened to Kenyanthropus platyops?”
When the talk was thrown open for discussion, [Tim] White took the microphone and began firing questions at Spoor about the degree of variation of the cheekbone position among specimens of A. afarensis and other hominin species. We took that into account, Spoor responded, and I just showed you a graph about it. I didnt ask you whether you took it into account; I asked you what it was, White said. Spoor, clearly frustrated, told the audience that he had no vested interest in this debate.
Hmmm…here’s an idle thought: Kenyanthropus differs from Australopithecus in having smaller molars (especially first molars), a flat lower face, and small (chimpanzee-sized) ear openings. Ardipithecus differs from Australopithecus in having small molars, big canines, and small ear openings. We now know from Ardipithecus that a hominin-like base of the skull does not reflect obligate bipedality. White argues that the face of KNM-WT 40000 is distorted, so that the “flat face” may be an illusion. There’s not a single measurable canine in the Lomekwi (Kenyanthropus) sample, nor are there any postcrania.
Could KNM-WT 40000 be a late-surviving Ardipithecus? Nah, doesn’t work. Dentally, the Lomekwi sample is basically like A. afarensis, except for having smaller molars. Ardipithecus has really small third molars compared to Australopithecus, and lacks the occlusal anatomy of the later hominins. And those small ear openings are shared with Australopithecus anamensis, so they’re not probative.
Still, it reminds us that there may be some shaking-out to do over the phylogeny of these early Pliocene hominins.