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Re: Hadrosaurs etc


From: "Andrew A. Farke" <andyfarke@hotmail.com>
Reply-To: andyfarke@hotmail.com
To: <dinosaur@usc.edu>
Subject: Re: Hadrosaurs etc
Date: Sun, 3 Nov 2002 08:24:22 -0700

A comment or two. . .

----- Original Message -----
From: "Tim Donovan" <msdonovan66@hotmail.com>
To: <rob@dinodomain.com>; <dinosaur@usc.edu>
Sent: Sunday, November 03, 2002 4:14 AM
Subject: Re: Hadrosaurs etc

> > >Hadrosaurs obviously faced a new predator; why are famine and disease
as
> >testable?<
We
> >can't test Tyrannosaurus sweeping like a Mongolian horde into the
lowlands,
>
> This scenario is testable-if a close relative of Tyrannosaurus is found
> in the Horseshoe Canyon, it would be disproven.

I meant the idea Tyrannosaurus originally evolved apart from the ornithiscian dominated lowlands, in Alamosaurus habitats.


I'm not sure about that. . .if I am correct, this argument relies on
correlations between the presence of T. rex and the absence of
lambeosaurines. Correlation does not imply causation.

Right, not by itself. The waning or extinction of lambeosaurs coincided with something besides the advent or spread of Tyrannosaurus - regression. But I doubt this was related to their demise. As inland taxa, lambeosaurs should have benefitted from regression, which increased their range. Tyrannosaurus may be more plausible, IF the relatively short legs and more bulky build of lambeosaurs made them slower than Anatotitan, and/or had less endurance.


You might be able to 
make *suggestions* as to biogeographical and ecological patterns, but it
would be extremely difficult (if not impossible) to prove or disprove
something.

Additionally, the stratigraphy and paleontology of the Horseshoe Canyon
Formation is being reworked by Dave Eberth and crew (see his JVP abstract).

I saw it, and contacted him about it; did you see his response, clarifying certain things, which I forwarded to the list? I suspected the mention of "saurolophine" bonebeds in unit 1 was an error.


I expect we haven't heard the last word on this unit.

Just my two cents. . .

Andy


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