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[Christine_Janis@Brown.edu: Fwd: Re: Dale Russel interview on NPR today (Friday)]



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-- MPR

------- Start of forwarded message -------
Date: Fri, 21 Apr 2000 10:25:04 -0400
From: Christine Janis <Christine_Janis@Brown.edu>
To: vrtpaleo@usc.edu, dinosaur@usc.edu
Subject: Fwd: Re: Dale Russel interview on NPR today (Friday)

>Apologies in advance for list duplication...
>
>Dr. Russell was also interviewed on this mornings Today show.
>
>They showed a nice 3d image of the "heart" and discussed what endothermy in
>this animal could have meant to its lifestyle.  His key moment was bringing
>up the single aorta that he claims is visible on the imaging.

        Guys, please note that this supposed heart structure (divided
ventricle and single aorta) is reflective of *high blood pressure*, not
endothermy per se. High blood pressure is necessary in endotherms because
they need a high rate of blood supply. However, large animals such as
(many) dinosaurs, with long necks and/or heads held high above the ground,
would also need high blood pressure to get blood to the brain, regardless
of metabolic rate.

        There is no simple functional correlation of a single aorta with
endothermy. This heart structure, fascinating though it may be, says
nothing about dinosaur metabolism, nor does it illuminate the issue of
bird/dinosaur relations.

        Christine

Christine Janis
Professor of Biology
Box G-B207, Brown University
Providence, RI 02912

phone: 401-863-2215
fax:   401-863-7544
email: Christine_Janis@Brown.edu
------- End of forwarded message -------