Re: birds as large as pterosaurs

[Brett Dunbar <brett@dimetrodon.demon.co.uk>]

In article <351AEB61.B00A5C52@flyinggoat.com>, Betty Cunningham
<bettyc@flyinggoat.com> writes
>It just occured to me to wonder--why are the largest flying pterosaurs
>so much larger than the largest flying birds? 
> Are there structural limits in bird anatomy that weren't present in
>theropods to limit size?  
>Is perhaps the actual weight of the feather body-covering a limiting
>factor? (seeing as the largest of pterosaurs could have been naked
>entirely and still capable of flight and not so with birds).
>For that matter, why don't we see bats as large as teh largest
>pterosaurs?  Is the weight of the fingers in the wingspan again a
>possible contributing factor?
>
>-Betty Cunningham

In fact at least one birds wingspan was about as great as Pteranodon
ingens, namely Argentavis magnificens the giant teratorn (related to the
new world vultures). It lived in Argentina about 6mya, had a wing span
of over 7 m and weighed about 120 kg making it somewhat heavier than
Quetzocoatlus northopi.

Source: Guinness book of Records
 -- 
Brett Dunbar