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Re: Ah ha! That's where therizinosaurs came from



David Marjanovic <david.marjanovic@gmx.at> wrote:

> I don't understand that. All I can imagine are adaptations to _parachuting_
> if they were capable of climbing up but not down.
>
> Arms that cannot be lifted above horizontal do look more suitable for
> gliding than for flapping and maybe even for climbing, the lack of tertials
> in *Archaeopteryx* is the outright opposite of what I'd expect of a glider
> or of an animal with recent gliding ancestry. And while this wouldn't be too
> detrimental in a parachuter (as shown by the "flying" frogs), asymmetric,
> lift-generating feathers don't fit parachuting well.


I think you and I are using different definitions of gliding.

http://dml.cmnh.org/2011Jul/msg00228.html

Under the definition of gliding advocated by Byrnes & Spence (2011)
for arboreal mammals, your 'parachuting' would qualify as gliding.




Cheers

Tim