Re: Miocene and Pliocene apes familiy tree?
Alex Duncan (aduncan@mail.utexas.edu)
21 Jul 1995 21:35:24 GMT
In article <3uo773$5s6@ra.ibr.cs.tu-bs.de> Joerg Rhiemeier,
rhiemeir@ibr.cs.tu-bs.de writes:
>Does anyone know more details about how the different miocene and pliocene
>apes (e.g. Proconsul, Ramapithecus, Sivapithecus, Kenyapithecus,
>Dryopithecus, Oreopithecus, Gigantopithecus, ...) relate to each other
>and to modern apes, and human? I think Proconsul is now considered to
>be the common ancestor of all the Greater Apes and Homo, and
>Ramapithecus and Sivapithecus are Pongines (members of the ancestorial
>line of orang-utans), and Gigantopithecus was related to the
>orang-utan line as well. But what about Dryo, Oreo and Kenyapithecus,
>and which was the common ancestor of chimp and human, and which the
>common ancestor of that one and gorilla (after the orang-utan line
>split off)?
Ramapithecus has been lumped into Sivapithecus, and doesn't exist
anymore. Both Siva and Gigantopithecus are now recognized as sister
groups of Pongo.
I don't think anyone really knows what to do w/ Kenyapithecus anymore.
It shows remarkable dental similarities to Sivapithecus, but I don't know
that anyone is comfortable with placing it in the Siva/Pongo clade. Most
of the material is dental, mandibular, or maxillary.
Dryopithecus is a controversial genus. It almost certainly lies either
just within the large ape clade, or as a sistergroup to the rest of the
large apes. Some of the premaxillary/maxillary anatomy looks "African
hominoid", but there are other features that may indicate relations w/
Siva/Pongo. As is usually the case, more material is needed.
Oreopithecus is weird. It almost certainly lies WITHIN the extant
hominoid clade (although there have been claims its a cercopithecoid).
It shows similarities to several different extant groups, including
gibbons and humans. I don't really think anyone knows what to do with it.
Proconsul IS NOT considered a common ancestor of the great apes and Homo,
or even of all extant hominoids. It is too primitive, lacking many
derived features shared by all living taxa. It is a sister clade to all
extant apes.
The best candidates for common ancestry of African 'noids (including
humans) are Dryopithecus and Ouranopithecus (= Graecopithecus?).
Ouranopithecus especially shows potentially apomorphic features (African
pattern premax/palate articulation, well-developed supraorbital tori)
that link it with African apes. There was a recent suggestion that
Ouranopithecus is in fact a sister group to gorillas, and the discoverers
of much of the recent material make a reasonable case for Ouranopithecus
being the earliest hominid (I use "hominid" in the traditional sense
here).
Another very interesting Late Miocene (~8 Myr) hominoid is Motopithecus
from the Samburu Hills of Kenya. The genus is based upon a single
maxillary fragment that superficially looks a great deal like a gorilla.
However, the enamel is thick.
There are no good candidates for a common ancestor of chimp and human.
A. ramidus is the closest thing to that yet, and it is probably
post-divergence (i.e., more closely related to humans than to chimps).
Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu
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