[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Tyrannosaurus was not a fat boy or girl



On Sun, Oct 23, 2011 at 3:30 PM, Vivian Allen
<mrvivianallen@googlemail.com> wrote:
> GSP: Briefly - systematically iterating a physical model (as distinct
> to simply 'adding as much plasticine as seems anatomically possible')
> to account for uncertainties in proportions and overall size is
> difficult to do without introducing small errors in scaling (if
> explicit scaling is actually used), the effect of which will be
> magnified the smaller the model is, unless (or even if, at very small
> scales) CNC tools are being used. Computer models make things
> considerably simpler and more controllable. If one wishes to observe
> the effects that enlarging the tail has on estimated mass and CoM, one
> simply needs to tap in an exact scaling exponent and re-run the
> analysis. As we discussed in the paper, it is very difficult to remove
> the effects of subjectivity when reconstructing morphology, but
> computerised modelling will always have the advantage of an
> immediately accessible and quantifiable relationship to the fossil
> material, to a degree not present in all but the most sophisticated
> physical modelling techniques.
to add to that: if there are studies of bone-to-soft tissue
proportions in extant animals of similar body (part) shape - why not
incorporate that? Allen et al. 2009 and Persons & Currie 2010 and my
admittedly much more restricted work give good data.

:) H
___________________________________
Dr. Heinrich Mallison
Abteilung Forschung
Museum für Naturkunde - Leibniz-Institut
für Evolutions- und Biodiversitätsforschung
an der Humboldt-Universität zu Berlin
Invalidenstrasse 43
10115 Berlin
Office phone: +49 (0)30 2093 8764
Email: heinrich.mallison@gmail.com
_____________________________________
Fere libenter homines id quod volunt credunt.
Gaius Julius Caeser



> On 23 October 2011 14:48, Jay <jayp.nair@yahoo.com> wrote:
>>
>>
>> Would be remotely helpful for readers if you posted the link to the comment 
>> on the Hutchinson et al paper, since you mention it here, Greg.
>>
>> http://www.plosone.org/article/fetchArticleComments.action?annotationId=info%3Adoi%2F10.1371%2Fannotation%2Fb76d947b-ec96-4954-84fa-31a558c17542&articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.0026037
>>
>>
>>
>> ________________________________
>> From: "GSP1954@aol.com" <GSP1954@aol.com>
>> To: dinosaur@usc.edu
>> Sent: Sunday, 23 October 2011 8:25 AM
>> Subject: Tyrannosaurus was not a fat boy or girl
>>
>> I've placed a comment with the Hutchinson et al. PLoS One paper on
>> Tyrannosaurus masses.
>>
>> Enjoy.
>>
>> It is becoming apparent that the uncertainties is restoring the power
>> dynamics of extinct animals are so extensive that it is not possible to 
>> calculate
>> whether or not adult Tyrannosaurus were slower or as fast than the
>> obviously fast juveniles. If someone eventually comes up with power 
>> calculations
>> estimating that an adult Tyrannosaurus could run 30-35 mph I will be happy 
>> but
>> not sure how it is more reliable than those estimating only 20-25 mph. We
>> are going to have to wait until time machines are available. I shall get to
>> work on that.
>>
>> Also do not quite get the plot in Fig 6 in the Hutchinson et al. paper. It
>> seems to show 10 yr old Tyrannosaurus not weighing anything. Odd.
>>
>> GSPaul</HTML>
>>
>