Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)

[dinoboygraphics@aol.com]

Sorry, I just got to this point in the discussion:

> > > Crampons have points directed in two directions. A set of 8 or so 
are on the bottom of the crampon for walking on icy / snowy surfaces. 
Two point forward from the front, to gain purchase on high angle or 
vertical surfaces, with the foot simply projecting into space. One can 
even stand with a single front directed point in the ice, is it is set 
well enough in the ice. But is such cases one is using ice axes or some 
such with one's arms.<<<

Um, crampon spikes are all essentially straight along the blade, for a 
very important reason: so you can get them out again!  Unless the 
second pedal claw was particularly straight, it would be near 
impossible to pull out of the substrate, especially if you've moved 
yourself up relative to the original point of insertation.  With manus 
claws this is less of an issue, since the axis of rotation is usually 
set below the point of entry even after pulling yourself up, but the 
toes have no such advantage, especially in non-splayed stiff-limbed 
maniraptorans.  Trying to make Archie an adapted climber is an act in 
trying to make the facts fit a theoretical preconception on how flight 
should begin (if it even began in an Archaeopteryx-grade paravian).

> > > My advice is to stick with skateboarding.Â<<<

They'd have to, as climbing vertical trunks would be right out.


Scott Hartman
Science Director


Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333

www.skeletaldrawing.com


-----Original Message-----
From: Dan Chure <danchure@easilink.com>
To: david.marjanovic@gmx.at
Cc: DML <dinosaur@usc.edu>
Sent: Sun, 7 Sep 2008 6:20 pm
Subject: Re: Campbell's even crazier than a MANIAC? (archeopteryx 
climbing)


I'm not sure what you mean by side-to-side. Crampons have points 
directed in two directions. A set of 8 or so are on the bottom of the 
crampon for walking on icy / snowy surfaces. Two point forward from the 
front, to gain purchase on high angle or vertical surfaces, with the 
foot simply projecting into space. One can even stand with a single 
front directed point in the ice, is it is set well enough in the ice. 
But is such cases one is using ice axes or some such with one's arms. 
My advice is to stick with skateboarding.Â
Â
DanÂ
Â
David Marjanovic wrote:Â
> > Setting aside true arboreality for the moment - how well would they 
>> be have been able to use their claws as crampons for ascending >> 
trunks, rocks, whatever?Â
> Â
> Don't crampons work side-to-side? Sickle claws worked top-down and > 
probably had a cutting edge. They were not round in cross-section.Â
>
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