Re: pteros have lift-off

[Augusto Haro <augustoharo@gmail.com>]

> Tim Williams wrote:
>
> Elongation of the forelimbs is a character that appears to be primitive for 
> coelurosaurs.

but not to the degree of Archaeopteryx, I suppose...

> David Peters wrote:
>
>> If you choose dinos or
>> Scleromochlus as sister taxa, you have long hindlimbs and
>> short forelimbs. The same if you choose Cosesaurus and
>> Sharovipteryx. No other taxa have been promoted seriously
>> with matrices.

But Bennett 96' provided a phylogenetic analysis also to suggest
pterosaurs were non-archosaurian Archosauriformes, which were more
likely quadrupedal. Not that I'm saying this hypothesis is superior to
the others.

A little question for anyone: is not at the beggining of the flapping
flight when more lowered are the wing tips (as in the "applauding" of
pigeons)?. Not suggesting pterosaurs "clapped", but that perhaps the
wing beat excursion range was somewhat superior at the beggining of
flapping flight than in later phases, after some flaps and gaining
some forwards inertia. How does this apparent greater excursion range
at the beggining of the flight (If true for other flyers and not
something only present in the pigeons in my city) scales with size?

I read above David P. indicated wings do not pass the vertical in
somewhat larger birds, as swan, while I would suppose they would need
an even greater effort than in the pigeon because of their greater
weight.

About the comparison between the forelimb jump and a downstroke: I
supposed the forelimb jump differed from a downstroke in mostly
implying forelimb extension, while the downstroke mostly implies
lowering an already extended wing. However, I accept that in both
cases the M. pectoralis lowered the humerus.