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

Re: Did dinosaur wings evolve for breeding display?/Longisquama



Dp wrote:

> > Never forget Dial's studies with young birds with
> small wings.
> 

Mike Habib wrote:
> The wings of juvenile chukars using WAIR are still larger
> than the forelimbs of Longisquama.  There are a host of
> other reasons that Longisquama would not be a good WAIR
> candidate, as well.  There is very little real evidence for
> even partial volancy in Longisquama at this time, but that
> does not mean it cannot have volant relatives.
> 
The point is this: before you get big wings that do fly, whether pterosaur or 
chukar, first you start with small wings that do not fly. I'm not claiming that 
Longisquama ran up trees in the manner of chukars, although you never know. 
Personally I like the arboreal leaping theory, but then there's a whole 'nother 
kettle o' fish. Sorry I wasn't more clear earlier. And to that point:


DP wrote:
> > Also the previews to a new Disney movie, Earth, show a
> duckling 'parachuting' to the leaf litter. Wing
> length is not as important as you imply.
> 

Mike Habib wrote:

> Wood ducks don't really parachute, so much as simply
> fall.  Their terminal velocity is quite low, and they fall
> onto leaf litter, so there is little need to speed
> reduction.  The falling ducklings do wave the forelimbs, and
> maybe produce some useful drag that way, but it is more
> likely that this is a reflex action related to an attempt to
> keep balance.

People don't really parachute when they jump out of planes, so much as simply 
fall either, but both have the sense to spread their limbs and flatten out, 
which, if that's all you got, that's what you use to slow your velocity and 
perhaps maneuver a wee bit That's the whole point here. 
> 

DP wrote:
> > Especially when you consider Longi's cousin:
> Sharovipteryx. Don't follow your preconconceptions.
> Follow the fossils. Flapping doesn't necessarily mean
> flying, either. Birds flap long before they fly
> ontogenetically.
> 
Mike Habib wrote:

> Yes, but for most species this is probably primarily a
> method of exercising the wings (which, in part, helps to
> stimulate strengthening of the forelimb skeleton).

Thank you for briefly saying yes, Mike. Exercising growing wings? Absolutely. 
Any thoughts on any adult fossil bird relatives with nonvolant anatomies 
flapping without being able to fly? Nowadays, what have you among nonvolant 
birds?
> 
> And to Jaime's points: yes early drawings do tend to need to evolve after a 
> few years, as we both agree. 

Regarding the multicusped teeth of Longisquama: look more closely. Did Sharov 
not comment on this? I thought he did. I don't reconstruct multicusped teeth 
based on sister taxa. The teeth of Longi. have different patterns than those of 
sister taxa. 

Jaime wrote: >>I measured all bones from a single photograph and from given 
scales from multiple papers to cross-reference, as well as the original Sharov 
work...<<

Good to hear you're not adverse to using photographs. Were you tracing with a 
pencil? Or using Photoshop? Photoshop provides an opportunity to virtually 
enlarge a photo to the size of a bedroom wall and to get rid of the halftone 
dots.

Jaime wrote: > The entire snout region is not to be trusted.< 

On the contrary, it is what is is... or was! It _is_ to be trusted. We just 
have to reconstruct it after crushing. Careful attention to detail will unwrap 
the mystery so we can "uncrack the eggshell", so to speak. We can argue the 
details later, because several opinions will ensue, certainly. And if I'm 
wrong, or you're wrong on one or several points I would hope someone would 
point that out because we need to get this right!

Right?

Working together for the common good.

David Peters