Fw: Tarbosaurus?

["Keith DeHaas" <kdehaas@cub.kcnet.org>]

Hi.

I wonder if we can really say there is a preservational bias against
juvenile tyrannosaurs.   Has enough tyrannosaur material been found to have
a sample size large enough to draw that conclusion from?

I mean, if I decided to ask one million people who they were going to vote
for in an election, I wouldn't assume a pattern based on the responses of
the first 20 or 30 people.

Keith

----- Original Message -----
From: Tracy Ford <tlford@ix.netcom.com>
To: Dinonet <dinosaur@usc.edu>
Sent: Saturday, July 22, 2000 5:26 AM
Subject: RE: Tarbosaurus?


>
>
>     Sure, just as soon as YOU provide evidence that the preservational
> biases againt juvenile tyrannosaurs were precisely identical in two
> different depositional environments on two different continents which
> already show evidence of other differences in preservation involving
> tyrannosaurs.  Can you, George?  I can't explain how you get such
unusually
> high preservation of tyrannosaurs in general in the Nemegt Formation
> compared to Hell Creek, but it seems to have happened regardless.  We're
> both just hypothesizing here, but your assumption that the preservation
> ratio of juvenile and adults should be identical in the Nemegt and Hell
> Creek Formations is unfounded.
>     The only real evidence we have whether or not the big and little
> Tarbosaurus specimens belong the same species or not is morphological, and
> morphological studies suggest there is a gradation in size and
morphological
> change between the little and big tyrannosaur specimens consistant with
> ontogenetic change.<< (Hey, I remembered to put that in) :>
> What articles are you using for the large number of juvenile Tarbosaurs? I
> don't recall the paper/s.
> Tracy
>
>
>
>
>