Re: Quetzalcoatlus mass

[Mike Habib <habib@jhmi.edu>]

I am in agreement with Greg Paul on this one. It is worth noting that  
Greg P. , Jim Cunningham, and Mark Witton all derive roughly the same  
body mass estimates for giant pterosaurs, using three different  
methodologies (in all three cases, the methodology works on extant  
species for confirmation).

At a quick glance, it seems that the slicing technique is basically  
overestimating at large sizes - hence it seems to work for living  
birds alright, and animals near that size range, but accumulates error  
at large body sizes. The methods used by the three authors above, by  
contrast, were verified on larger animals.

Incidentally, Quetz was probably a long-distance flyer, just not by  
continuous flapping flight.

Cheers,

--Mike H.


Sent from my iPhone

On May 21, 2010, at 4:10 PM, GSP1954@aol.com wrote:

> I was the first to explain that Quetzalcoatlus was far more massive  
> than
> the conventional wisdom. I was in charge of the restoration for Paul
> McCready's robotic QN project and quickly realized that the skeletal  
> framework was
> way to big to accomodate the human-like 70 kg mass thought necessary  
> to
> achieve flight, and I published more realistic weights starting in  
> 1987 in Nature.
> As one who thinks superpterosaurs were real massive the new estimate  
> of
> about a half tonne is a real stretch. The half size Q. sp are  
> sufficient to get
> a reasonable volumetric estimate, and scaling up from that results  
> in a
> quarter tonne for Q. northropi assuming a normal avian specific  
> gravity. The
> existence of what appear to be fully developed wings on the  
> superpterosaur
> indicate it was a true flier, albeit perhaps a short range burst  
> flier. A
> number of researchers including myself have shown that the span/mass  
> ratio was
> simialr to some gliders and there was plenty of muscle power to take  
> off.
>
> GSPaul</HTML>