Re: Prior to the `last common ancestor'

Alex Duncan (aduncan@mail.utexas.edu)
6 Nov 1995 23:53:44 GMT

In article <47lu7t$bes@nntp.ucs.ubc.ca> pete, VINCENT@Erich.Triumf.CA
writes:

>Ok, so of these earlier (older than 14mya) creatures, how much
>post cranial remains do we have, and what sorts of modes
>of locomotion do they indicate?

There is a lot of postcranial material available for Proconsul.
Interpretations vary. I suspect a consensus view might be that Proconsul
was very much like a Howler monkey in terms of its postcranial anatomy
(minus the tail) -- i.e., it was a relatively slow moving arboreal
quadruped with some suspensory capacity. Also, Proconsul (esp. P.
nyanzae & P. major) is thought to have come to the ground pretty
frequently.

There isn't nearly as much material available for other taxa.

>If Kamoyapithecus is older than proconsul, does that mean it
>had a tail, or is there not enough material to say?

There isn't enough material.

>Do we have any idea of what primate stock the homonoids sprang
>from, ie which old world monkeys (if any) are we closer to?

We are equidistantly related to all OW monkeys. The hominoids arose from
a generalized catarrhine stock (monkeys are too specialized to have given
rise to hominoids). The best current model for an ancestor of both
cercopithecoids and hominoids is Aegyptopithecus, from the Fayum at ~35
Myr. There's a pretty good gap between Aegyptopithecus and
Kamoyapithecus.

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu