Re: Flightless pterosaur indicators

[David Peters <davidpeters@att.net>]

I doubt they evolved as sexual displays, as fashionable as those types of 
suggestions are nowadays. It's just too easy and plausible to picture a flying 
squirrel-type membrane stretched from digit IV to the leg as the precursor to 
the pterosaur wing.

That's what Augusto Haro argued earlier in the thread. I think he's on the 
right track. Birds can afford to lose the musculature while becoming 
flightless- the organs the muscles power are no longer used for locomotion. 
Pterosaurs, as quadrupeds, would still need ample musculature up front to move 
about. My vote for chief flightless pterosaur indicator would be greatly 
reduced wingspan.

~ Abyssal

It is easy to picture a flying squirrel-type membrane. Nearly everyone who has 
looked at this problem has started with this very proposition. Unfortunately, 
it turns out there's no support for it whatsoever. All such reports have been 
pure imagination-- and I'm not being insulting here -- by the author's own 
words and the term "hypothetical" sprinkled throughout their works. The 
opposite, however, has been reported in the fossil record. Distal origin of the 
wing membrane.

Sorry I missed Augusto's note. If I'm not copied, I get all posts in the 
Archive, a day later or later than that, and I, unfortunately, don't read all 
of them. So to that point, would the shoulders of flightless pterosaurs need to 
be as robust as the shoulders of flighted ones? I wouldn't think so. 

David Peters