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RE: Yet more on dinosaur quad climbers



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> Date: Fri, 12 Jul 2013 09:25:41 -0400
> From: GSP1954@aol.com
> To: dinosaur@usc.edu
> Subject: Yet more on dinosaur quad climbers
>
> Somebody had to change the title of this thread.

>
> TW -There isn't even a reversed or incumbent hallux in these "arboreal"
>
> theropods! Bit odd for an "arboreal" dinosaur, no? If the foot was
>
> no longer used in terrestrial locomotion, why was the hallux so short
>
> and so thoroughly un-reversed?
>
> Classic example of limited thinking. As I have said so many times,
> quadrupedal climbing dinosaurs may not have needed the reversed hallux 
> arboreal
> bipedal birds need. Might have even been a disadvantage for quadrupedal
> climbers. There are lots of climbing quadrupeds without opposable digits.

...and without stiff tails.  (tarmanduas can be bipedal in trees, but they use 
their tails for gripping)

Seriously, you keep coming back to modern climbing quadrupeds, despite how that 
entire branch of the Dinosaur family tree (Eoraptor thru Hoatzin) has no 
quadrupedal species.

>
 Quadrupedal dinosaur climbers would have been very
> different from bipedal climbers, the obsession with the need for a reversed
> hallux for dinosaurs with long arms and hook clawed fingers to climb is not
> scientific. Think outside rigid boxes.

Okay...if memory serves, crocodiles have sharp claws, not always the dulled 
flat claws you say all terrestrial animals have.

> TW seems fixated on the idea that there were ground dwelling predatory
> dinosaurs that evolved strongly curved, sharp tipped talons on toes 2 & 3 for
> predation. It is dubious that this would happen in dinosaurs that still had
> tooth filled jaws and long fingered hands,

?
why is that dubious?

> TW - Many modern birds use their wings in combat, sustaining damage to the
>
> feathers in the process; they live to fight another day. So I'm not
>
> convinced by the claim that theropods with long pedal feathers were so
>
> fastidious that they avoided the ground altogether.
>
> Again the use of extreme lanquage when inappropriate. Never said that
> Microraptors "were so fastidious that they avoided the ground altogether." But
> they were not idiots. Occasional use of wings in combat is not the same as
> constantly abrading flight feathers by chronic contact with gritty ground. 
> What
> bird does that? Why have such big spectacular feathers evolved for flight
> and then live a lifestyle that will maximize damage to them? Does not make
> sense. Evolution is not that stupid.

  like peacock tails and deer antlers - if you live a dangerous life and can 
still have big spectacular stuff, that helps attract a mate.