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RE: Lack of Running Giant Theropod Tracks





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> Date: Sun, 28 Nov 2010 20:49:19 -0500
> From: d_ohmes@yahoo.com
> To: dinosaur@usc.edu
> Subject: Re: Lack of Running Giant Theropod Tracks

> > I'm guessing that you were intentionally exaggerating with the boy scout 
> > comment
 
> Not really. A gutsy young lad from (e.g.) Wyoming could do in a
> brachiosaurus in if he could get a bull rope on him in the right spot --
> there were portions of the neck that were inaccessible to the sauropod.
> It would seem that finding a convenient tree to scrape the kid off with
> might work. But not if that trusty Randall knife was really sharp. No time.

You seem to continue to forget that sauropods had neck ribs, which were wrapped 
in muscle, tendons and ligaments. They usually screw this up in movies by 
giving sauropods tube like necks, when in reality the ribs would probably show 
under the skin and the underside of the neck would be somewhat flat. The point 
is that the arteries of their necks were far more well protected than ours 
despite being much longer. 
 
> There are none, unless you count the relatively tiny giraffes. Even
> there, where is the tall biped w/ neck-encompassing jaws? We have to
> stick with the morphological realities the geo-record gives us.
 
Video of lions killing a giraffe by climbing up its neck and biting it.
 
http://www.youtube.com/watch?v=m2FPG2wXhXY
 
Like I said, do I think giant theropods could kill giant saurpods? yes. Do I 
think it would have been easy? NO. Giraffes can put up one hell of a fight: a 
single kick from a giraffe can kill a lion in the same way I imagine the tail, 
neck and clawed feet of a sauropod could kill a Giganotosaurus.
 
 http://www.youtube.com/watch?v=FxpKwl1jOug
 
You'll notice they are eating a newborn giraffe while the mother attempts to 
stomp them to death.
 
> My take -- unless dino nerves were really special, the really big guys
> were, in fact, really really slow.
 
Thank you for the link. I'll read through it and let you know what I think, 
though by just skimming through it, I think "really, really, slow" may be a bit 
of an exaggeration.
 
>biped in deep mud would be in deep
> doodoo.
 
Are you suggesting that sauropods lived in swamps?
 
> I do assume they were relatively slow -- as in the slowest ever. I also
> assume they could and did get tired and de-hydrated. Anyother
> assumptions are special pleading when assessing the respective
> capabilities -- as is the old "they were just so big the theropods would
> be terrified" behavioral argument.

Well between your "boy scout" example and the argument that a "theropod in a 
tree" could bite off their head, you're leaving me a little confused as to how 
helpless you imagine things things to have been. There is a big difference 
between saying things like that and simply stating that they might have gotten 
tired or were the slowest of the dinosaurs.
 
You also seem to have to have gotten the impression that I think giant 
theropods *never* hunted sauropods. I don't think that at all! Thinking that a 
theropod would have hesitated to attack an animal large enough to kill it with 
its mass alone is not special pleading. As Habib has pointed out, most 
predators do not make a habit of attacking animals that are several times 
larger than themselves...unless they are in packs. Pack or "mob" hunting 
allosauroids may have been very effective hunters of sauropods. Like I said, 
the focus of my argument was more on the fact that there may be examples such 
as Tyrannosaurs, whose primary food source, the juveniles of Triceratops, may 
have been too fast to catch if Tyrannosaurs could not run. 
 
>No, it isn't. Sauropod necks were mostly air
 
And muscle, tendons, ligaments large neck vertebrae etc.. Now of course an 
animal like T. rex probably could have crushed the neck on an alamosaurus since 
their jaws could crush bone, but the more blade like teeth of some other 
theropods I'm not so sure about. 
 
>The other half of the coin must not be ignored -- a sauropod in a swamp or 
>other >place of uncertain footing, with deep footprints and knocked down trees 
>inter->laced everywhere, was nearly as safe from the bipedal theropods as we 
>are >today :D...
 
That is actually a good point, but I think you may be pushing some other 
arguments into the extreme in order to make it. I think you are bordering on 
setting up a false dichotomy by over blowing their vulnerability. These animals 
would not have to of beeen clumsy and borderline helpess for your idea to be 
true.
 
>Could be. Actually, didn't the allosaurids and the sauropods disappear for N 
>>America at approximately the same time?
 
I think so. I find it interesting that (some of) the allosauroid group kept on 
truckin down south where there were plenty of sauropods; it could be related, 
or it could also be coincidence. 
 
>And 25 mph is fast. Too fast, imo.
 
  I find it interesting that Tyrannosaurids were probably the most cursorial of 
the giant theropods, and they probably also hunted sauropods much less than 
allosauroids. With ceratopsians and ornithopods being faster than sauropods, I 
would guess that Tyrannosaurs were probably pretty fast for their size. My 
guess is that if juvenile ceratopsids were indeed as fast as rhinos, than 
Tyrannosaurs may have been as fast. I'm also guessing that allosaurids/oids 
were pretty effective sauropod killers if they worked together as a group. I'm 
also guessing Some retention of running ability would have been useful for 
solitary or younger carnosaurs in the same way that elephant killing lions 
still hunt kill animals smaller than themselves. However, the key word here is 
*guessing*. 
 
 
Simeon Koning