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

Re: the bipedal ptero-challenge



Mike Taylor wrote:
> 
> Wow.  You've done a great build-up job on this Mystery Technique.  Are
> you going to tell us what it is?  :-)

I wasn't planning to, because we haven't published yet.  I've described
it verbally to a number of people beginning with my talk with Paul
MacCready at SSA '99.  I did give a short one paragraph extreme
oversimplification in another post to the list last night.
 
> It seems like only yesterday that the aerodynamics/biomechanics guys
> were telling us that _Pteranodon_ was at the absolute limit of how big
> an animal could be and still fly;

Not all of them.  Some of the paleo guys may have been providing
inappropriate input about constraints and parameters, listening to what
the aerodynamics guys were saying about the effects of those
constraints, and then misinterpreting the response. Or, are you saying
that Quetz couldn't fly?

> yet here we are with _Q._ not just
> flying but lunging up into the air without a run-up.

Dropping the usual caveats, Quetz doesn't lunge up into the air.

>  Don'tcha just _love_ those Fundamental Size Limits?  ;-)

Where flight is concerned, they exist, just like they always did. I've
not really tried to establish the limits as they might apply to
pterosaurs, but suspect the big azhdarchids probably would have topped
out at about 13 meters in span (42-43 feet or thereabouts). That guess
is based on the difference in shape between corresponding bones in the
wings of Qsp and Qn and by looking at Qn to roughly visualize how much
room was left for additional morphing for robustness, muscle attachment
surface, and leverage. I could easily be off some, even quite a bit.
Constraints would be somewhat different for Ornithocheirids and
Pteranodontids.  But due to the physical constraints of launching, with
increasing size, it would eventually become impossible to launch. Don't
look too hard for Dumbo the flying elephant in the fossil record.