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RE: Taking the temperature of dinosaurs?



I don't know. If this work follows the trend for other studies that have 
compared automatic endotherms to bradymetabolic "ectotherms" I suspect the 
results are going to show a lot of bleed over.

While Dan's paper may have cited a captive animal there are plenty of other 
papers that show ectotherms behaviourally regulating high body temps to within 
1-2 degrees C (a lot of work by Seebacher comes to mind).

Jason

--- On Wed, 5/26/10, John Scanlon <riversleigh@outbackatisa.com.au> wrote:

> From: John Scanlon <riversleigh@outbackatisa.com.au>
> Subject: RE: Taking the temperature of dinosaurs?
> To: dinosaur@usc.edu
> Date: Wednesday, May 26, 2010, 8:11 PM
> Note that the Varanus salvator paper
> Dann linked to concerned a captive
> individual in a thermal gradient, meaning a substrate at
> its preferred body
> temperature was constantly available during the study.
> There are few places
> where this would be the case year-round (or even through
> the growth season)
> in the wild.
> 
> I think it will be very interesting to apply this 13C:18O
> method to known
> ectotherms from a range of places and times, as it'll
> provide a whole
> 'nother dimension to inferences about habitat and behaviour
> differences
> within local faunas (proxy for
> terrestrial/aquatic/arboreal,
> diurnal/nocturnal, heliotherm/thigmotherm) as well as
> testing/validating the
> snake-body-size palaeothermometry approach proposed in the
> case of
> Titanoboa.
> 
> Plus one of the coolest things (claimed) in the paper is
> that the method
> allows assumption-free calculation of the environmental
> delta18O, and thus
> takes the average temperature of the habitat as well as
> growth-weighted
> average for the animal concerned. I won't be surprised if
> it's possible to
> distinguish ectotherms and endotherms in many cases, when
> multiple taxa are
> compared within a fauna.
> 
> -----------------------------------------------
> Dr John D. Scanlon, FCD
> Riversleigh Fossil Centre, Outback at Isa
> riversleigh@outbackatisa.com.au
> http://www.o
Fossil-Education/Palaeontologist.aspx
>  
> "Get this $%#@* python off me!", said Tom laocoönically.
> 
> -----Original Message-----
> From: Dann Pigdon [mailto:dannj@alphalink.com.au]
> 
> Sent: 26 May, 2010 11:38 AM
> To: dinosaur@usc.edu
> Subject: Re: Taking the temperature of dinosaurs?
> 
> On Wed, May 26th, 2010 at 11:19 AM, "Thomas R. Holtz, Jr."
> <tholtz@umd.edu>
> wrote:
> 
> > It is worth noting that the analysis cannot at present
> resolve
> > endotherms
> > vs. ectotherms. It is just a thermometer: it is not a
> thermometer
> > with a
> > time component.
> > 
> > Too many people in the press about this seem to think
> that
> > warm-blooded
> > animals actually have higher body temperatures than
> cold-blooded
> > ones.
> 
> Indeed. Some varanids are able to regulate their body
> temperatures to about
> 35 C, with a 
> precision of +/- 1 C.
> http://www.jstor.org/pss/30155835
> 
> That's higher than your average monotreme (30-32 C).
> 
> -- 
> _____________________________________________________________
> 
> Dann Pigdon
> GIS Specialist           
>          
>    Australian Dinosaurs
> Melbourne, Australia         
>      http://home.alphalink.com.au/~dannj
> _____________________________________________________________
> 
> 
>