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Re: Fw: late night thoughts: misunderstand what?

On 6/18/07, don ohmes <d_ohmes@yahoo.com> wrote:

----- Original Message ----
From: Andreas Johansson <andreasj@gmail.com>
To: d_ohmes@yahoo.com; dinosaur@usc.edu
Sent: Sunday, June 17, 2007 5:06:34 PM
Subject: Re: Fw: late night thoughts: misunderstand what?

On 6/17/07, don ohmes <d_ohmes@yahoo.com> wrote:

> ........... I think it unlikely that the first seriously big theropod 
appeared before or after the first seriously big sauropod (within the margin of 
error). They probably moved pretty much in lock-step. From the functional 
perspective, top herbivore/top predator form a predation pair. The fact that the 
most extreme cases of giantism in both occurred simultaneously in geological time 
is, in my view, evidence for an arms race

Simultaneous occurence means nothing if you've got non-overlapping
ranges. *Tyrannosaurus* and *Puertasaurus* are both Maastrichtian and
of near extremal size for thero's and sauro's respectively, but found
on different continents. The sauropods actually known from tyrannosaur
turf are, AFAIK, all comparative runts.

............. It seems to me that late in the game, finding the respective maximals well-separated might be viewed as support for a theropod/sauropods size race that began 'at the beginning'.

Which beginning? Tyrannosaurs achieved gigantism independently from allosaurs, for a start. Where there any really large sauro's around when the tyrants grew big? Did those mega-sauro's grew bigger in lock-step until some point where the tyrants won?

Your idea need to be anchored in actual spatiotemporal distributions of fossils.

Andreas Johansson

Why can't you be a non-conformist just like everybody else?