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Re: New paper on modeling dinosaur physiology



The Barrick and Showers data have always been a bit controversial. Part of it 
had to do with recrystalization of isotopes (homogenizing the data and making 
things appear more stable than in real life) as well as the extensive overlap 
between endotherms and ectotherms on the oxygen isotope scale (see Kolodny et 
al. 1996 for a good summary). Barrick and Showers 1996 also used a single, 
badly preserved lizard skeleton as their ectotherm model (along with a whole 
lot of assumptions of how ectotherms "should" work). It was both smaller than 
any of the dinosaurs measured and crumbly enough that many bones were 
represented by only one or two samples, skewing the final results.

Jason

Kolodony, Y., Luz, B., Sander, M.,  Clemens, W.A. 1996. Dinosaur Bones: Fossils 
or Pseudomorphs? The Pitfalls of Physiology Reconstruction from Apatitic 
Fossils. Palaeogeo. Palaeoclim. Palaeoeco. Vol. 126:
161–171
 



----- Original Message -----

> From: "Thomas R. Holtz, Jr." <tholtz@umd.edu>
> To: david.marjanovic@gmx.at
> Cc: dinosaur@usc.edu
> Sent: Monday, 12 August 2013 8:46 PM
> Subject: Re: New paper on modeling dinosaur physiology
> 
> Yes, and they show stable body temps. This paper is problematic on a
> number of issues.
> 
> http://www.jstor.org/discover/10.2307/2401221?uid=3739704&uid=2&uid=4&uid=3739256&sid=21102547345933
> 
> http://www.jstor.org/discover/10.2307/3515240?uid=3739704&uid=2&uid=4&uid=3739256&sid=21102547345933
> 
> 
> 
> On Mon, August 12, 2013 8:11 pm, David Marjanovic wrote:
>>>  Uninsulated small taxa, and all juveniles, presumably would have been
>>>  ectothermic, with consequent diurnal and
>>>  seasonal variations in body temperature.
>> 
>>  Are there any isotope data from whichever ones count as "small"?
>> 
> 
> 
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu    Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> http://www.geol.umd.edu/~tholtz/
> Fax: 301-314-9661
> 
> Faculty Director, Science & Global Change
> Fax: 301-314-9843
> 
> Mailing Address:    Thomas R. Holtz, Jr.
>             Department of Geology
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>