Classifying apes & relatives

[John Grehan]

I should add that one need not pay much attention to the lack of molar
cingula as a character. It appears to be consistent within the orangutan
clade and between living orangutans and humans, but outside that there may
be too much variability for the character to be definitive about relationships.

John


At 10:25 AM 5/27/2003 -0400, John Grehan wrote:
>I know far too little about even higher primate systematics to start on
>about the formalities of classification, but I guess that won't stop me
>from a making a couple of (poorly?) informed comments   On the premise that
>humans and orangutans are each other's closest living relatives, I see the
>possibility of two major clades:
>
>The first is the immediate 'human' line that might include Homo and
>Australopithecus, and also perhaps Kenyanthropus (whether or not it is
>subsumed within Australopithecus), and Orrorin - although admittedly its
>not well known.
>
>The second is an Orangutan line. There are several fossil taxa that are
>possibilities, although its also possible (and well beyond my current
>knowledge to know) that some are actually part of the human line). Taxa
>that might be included are Sivapithecus (well accepted as the closest
>sister group to orangutans), Lufengpithecus, Gigantopithecus (both also
>closely allied with orangutans), Ouranopithecus, Ankarapithecus, and
>Hispanopithecus.
>
>The above taxa of both clades share thick dental enamel, a single incisive
>foramen (where known), and lack or have poorly developed molar cingula. I
>haven't had a chance yet to learn about the shoulder girdle which also
>exhibits Human-Pongo features.
>
>Outside these clades things get a bit more fuzzy. There are two taxa -
>Kenyapithecus and Afropithecus with thick dental enamel, but Afropithecus
>has two incisive foramena and well developed molar cingula, and then there
>is Rudapithecus with thin dental enamel, a single incisive foramen, and
>lacking molar cingula.
>
>Then there are three other taxa with thin dental enamel for which the upper
>palate is not known at all or well enough to determined the incisive
>foramen - Equatoriaus (reduced molar cingula), Sahelanthropus (molar
>cingula?), and Ardipithecus (molar cingula?).
>
>That's my current speculation. Its frustrating that the upper palate is
>either unknown, or too poorly preserved to confirm the incisive foramen in
>several taxa.
>
>John Grehan
>
>At 07:56 PM 5/23/2003 +0000, Ken Kinman wrote:
>>Dear All,
>>     Well since we are on the subject, here is the part of my "sketchy"
>>preliminary primate classification showing how the main families of apes and
>>relatives may have split off.  I recognize broader (fewer) families than
>>most workers.  Family Pongidae (great apes excluding "hominids sensu
>>stricto") is obviously paraphyletic.  The recently described genus
>>Kenyanthropus is placed within Australopithecus.  Orrorin is too fragmentary
>>and controversial to place in either Pongidae or Hominidae with any
>>confidence.
>>     Anyway, if a chimp-human clade is disproven, the {{Hominidae}} exgroup
>>marker would just need to be moved up closer to Pongo.  Once again, this
>>kind of modular approach to classification gives us flexibility without
>>sacrificing stability.
>>
>>  1  Cercopithecidae
>>  2  Propliopithecidae
>>  3  Pliopithecidae
>>  4  Proconsulidae
>>  ?  Oreopithecidae
>>  5  Hylobatidae
>>  6  Pongidae
>>        1  Dryopithecus
>>        ?  Ouranopithecus
>>        2  Lufengpithecus
>>        B  Sivapithecus
>>        C  Pongo
>>        3  Gorilla
>>        ?  Samburupithecus
>>        4  Pan
>>        5  {{Hominidae}}
>>_a_ Hominidae
>>        1  Ardipithecus
>>        ?  Sahelanthropus
>>        2  Australopithecus
>>       _a_ Homo
>>
>>              ----- Cheers,
>>                      Ken Kinman
>>
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>Dr. John Grehan
>Director of Science and Collections
>Buffalo Museum of Science
>1020 Humboldt Parkway
>Buffalo, New York 14211-1293
>Voice 716-896-5200 x372
>Fax 716-897-6723
>jgrehan at sciencebuff.org
>http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
>http://www.sciencebuff.org/HepialidaeGate.htm

Dr. John Grehan
Director of Science and Collections
Buffalo Museum of Science
1020 Humboldt Parkway
Buffalo, New York 14211-1293
Voice 716-896-5200 x372
Fax 716-897-6723
jgrehan at sciencebuff.org
http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
http://www.sciencebuff.org/HepialidaeGate.htm