Re: [...] systematics & the DML & a last comment (short!)

[Stephan Pickering <stefanpickering2002@yahoo.com>]

--- David Marjanovic <david.marjanovic@gmx.at> wrote:
> > (the argument "cold" killed
> > dinosaurs, is more applicable to sauropods, as
> Roger
> > Seymour's excellent research demonstrates they
> were
> > not endothermic, than to other clades).
> 
> Searching the archives for "Roger Seymour" doesn't
> give more information on
> this... interesting research, searching for
> "Seymour" does, though:
> http://www.cmnh.org/dinoarch/1995Sep/msg00314.html.
> In this post HP GSP uses
> Seymour's 1976 paper to _support_ endothermic
> sauropods, as he & Leahy do in
> their 1994 paper.
> 
> > Some dinosaurs
> > survived in isolated geographical areas well into
> the
> > Paleocene (as James Fassett and Spencer Lucas have
> > explicated),
> 
> but only if we trust their interpretation of
> magnetostratigraphy. "Isolated
> geographical area"? New Mexico? Sure?
Roger Seymour has continued his research on
sauropod/dinosaur cardiovascular systems since his
1976 Nature paper:
R.S. Seymour and K. Johansen, 1987. Blood flow uphill
and downhill: does a siphon facilitate circulation
above the heart? Comparative Biochemistry & Physiology
88:167-170
R.S. Seymour, A.R. Hargens, T.J. Pedley, 1993. The
heart works against gravity. American Jour. Physiology
256:R715-R720 
R.S. Seymour & A.J. Blaylock, 2000. The principle of
Laplace and scaling of ventricular wall stress and
blood pressure in mammals and birds. Physiological &
Biochemical Zoology 73(4):389-405
R.S. Seymour and H.B. Lillywhite, 2000. Hearts, neck
posture and metabolic intensity of sauropod dinosaurs.
Proc. Royal Soc. London B267:1883-1887
The 2000 paper, especially, is of importance. Coupled
with Matt Bonan & team's work on sauropod locomotion,
and by careful inference from foraging strategies of
extant megaherbivores, population dynamics of
sauropods can be extrapolated, using the probable
physiological constraints inherent in sauropod
anatomy.


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