[Taxacom] Richmond and Jungers on Orrorin?

[John Grehan]

The paper by Richmond and Jungers seemed to mix up evidence of
bipedalism with evidence of relationship within bipedalism. In their
multivariate cluster analysis (Fig. 1B) they group Orrorin with
Australopiths rather than Homo, and refer to this arrangement as
summarize "affinities". If they are implyin that the mulivariate
simialrity is evidence of phylogenetic relationship then they have the
anomaly of grouping the great apes with each other as a monophyletic
group, with African apes being more closely related to orangutans than
humans. Any comment?

John

> -----Original Message-----
> From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-
> bounces at mailman.nhm.ku.edu] On Behalf Of Kenneth Kinman
> Sent: Wednesday, May 13, 2009 2:05 PM
> To: taxacom at mailman.nhm.ku.edu
> Subject: [Taxacom] Orrorin a hominid?
> 
> Dear All,
>       One paper which indicates that Orrorin should be placed near
> Australopithecus in Hominidae (sensu stricto) is Richmond and Jungers
> paper (March 2008 in the journal Science) on the femoral structure of
> Orrorin.  They make a good case that it was bipedal.  I believe the
case
> for bipedality in Ardipithecus is still based on single toe bones (and
> that argument seems more of a stretch to me).
>       And of course, we know that Orrorin also had thicker tooth
enamel,
> like Australopithecus, whereas Ardipithecus has thinner enamel like
> chimps.
>       The one thing that still troubles me about Orrorin is its canine
> tooth, which is very chimp-like.  I just wonder if perhaps the
earliest
> hominids might have been sexually dimorphic in this character.
Perhaps
> males of Orrorin still retained a chimp-like canine, but the females
had
> already begun the reduction of this tooth.  As far as I know, we still
> only have a single canine tooth from Orrorin, but I am hoping for more
> material to be discovered.
>             ---------Ken Kinman
> 
> 
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