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Re: New bird /pterosaur flight paper in PLoS ONE



Comments inserted,
JimC

----- Original Message ----- From: "Mark Witton" <Mark.Witton@port.ac.uk>
To: <dinosaur@usc.edu>
Sent: Thursday, April 30, 2009 3:59 AM
Subject: Re: New bird /pterosaur flight paper in PLoS ONE



1) This is all based on 'albatross-like animals', but plenty of
pterosaurs were nothing like albatross in wing shape or body
proportions.

I agree. When you take the neck and head proportions into account, the similarity declines even more.


Capping a limit on maximum flight mass based on one very
derived group of birds would be like scaling-up a skink to estimate the
maximum masses of sauropods: they're different beasts, and shouldn't be
treated so interchangeably when it comes to scaling.

Mark, that's a great comparison and very true.

Sato and chums need to explain why these chaps
retain so many characters related to flight but exceed their maximum
theoretical wingspan:

I Agree.

3) I don't quite see how they can justify their 93 kg mass for
Pteranodon and 274 kg estimate for Quetzalcoatlus:

I'd like to see the cross sections that lead to a 274 kg Quetz

neither has
particularly procellariiform-like proportions and yet, again, Sato and
friends only use this group to extrapolate masses for these pterosaurs.
My own estimates for Pteranodon and Quetzalcoatlus based on
extarpolations of bird mass are 60 and 150 kg, respectively - quite
different from their procellariiform-alone estimates.

Using a different method, I'm a bit lighter than you for Pteranodon, but match your 150kg estimate for the average weight of the large version of Quetz. A 274 kg Quetz would be quite tubby.


Once again,........Sheesh.

Yeah.

I guess I could go on about the general lack of consideration for all
sorts of recent work on pterosaur mass and flight (they could really do
with a copy of Mike Habib's Zitteliana paper, for instance - how can
they explain the stupidly-robust humeri of big pterosaurs if they're
doing little more than standing around on them?),

They're shaped that way so Alley Oop could use them for clubs :-(

If I can be bothered, I might write a
proper rebuttal.

Please do, Mark. I'm not going to.