[mailto:email@example.com]On Behalf Of Darryl
Sent: Friday, July 06, 2001 12:02
Subject: Re: Rauhut's Thesis
At 05:05 AM
7/6/2001, you wrote:
"Although the chance of finding
fossils of the population directly ancestral to later species is very small, a
cladist can recognize a potential ancestor as one which:
a) shares derived features with the hypothesized descendant;
b) lacks derived features unique to itself;
c) is found stratigraphically lower than the descendants; and (it would be
d) is found in a region later inhabited by the descendants.
Any fossil which qualifies for aspects a and b is called a
"metataxon". Thus, potential ancestors are metataxa which occur
earlier than the hypothesized descendants."
So a metataxon is technically a species that
shares synapomorphies with its descendent, but hasn't developed apomorphies of
its own. I see how this could happen, but don't think any dinosaurian
examples have been found yet.
I have heard of MOR 590 (Daspletosaurus sp.) described as a metataxon. The
justification for this was that it had derived features of BOTH T. rex AND D.
torosus, but had no derived features of its own. I am still waiting for a
formal description of it (and other Daspletosaurus material, for that matter)
before this gains credibility.
On another note, why do we find out about finds from remote parts of the world
and get preliminary descriptions of them within a year, yet wait ten plus years
for descriptions of animals found within 500 km of well established museums?
because the paleontologist are to DAMN BUSY!!! They have other projects, other
things come up, etc. And yes, I do also find it a bit annoying also, BTB.
Tracy L. Ford
P. O. Box 1171
Poway Ca 92074