Re: Quetzalcoatlus questions

[GSP1954@aol.com]

Aside from the structural impossibility of giant fliers diving into water, it 
should be remembered that azhdarchids were continental rather than marine and 
would not have had deep water to dive into.  

According to Marden 1994 Am J Physiol 35:R1077 at 250 kg flier with a normal 
amount of flight musculature would be able to take off subvertically if the 
flight muscles are biased towards short burst fibers like those of turkeys, 
which take-off without running. The hindlimbs also provide important power in 
nonrunning takeoffs. If lower burst power, longer endurance flight muscle 
fibers are assumed then a running takeoff is necessary. This is not really 
size dependent. 

If 12 m span giant pterosaurs weighed 250 kg, then the span/mass relationship 
falls close to the general flying animal line, and is similar to small 
sailplanes. This is discussed in DA. 

Greg Paul