RE: Lack of Running Giant Theropod Tracks

[Sim Koning <simkoning@msn.com>]

I think the strongest analogy for how dangerous Triceratops may have been to an 
individual Tyrannosaur rex can seen in an African boar and their ability to 
violently attack leopards  http://www.youtube.com/watch?v=E4fIiijYiOY
 
Most large ceratopsids were not only armed with horns long enough to kill a 
tyrannosaur, they were also armed with a beak powered by massive jaw muscles. 
Ceratopsians may have been omnivores like modern suids (pigs) and it may not 
have been that uncommon for a bull Triceratops to drive a lone Tyrannosaur from 
a kill so it could eat it itself (Greg Paul speculates on this in his Field 
Guide). Considering the limited turning rate (1 or more seconds for a 45 degree 
turn) suggested by Hutchinson and his colleague's work, I have a -very- hard 
time believing that a single adult Tyrannosaurus rex would have been able to 
attack an adult Triceratops without enormous risk. Of course all this would 
probably mean is that solitary Tyrannosaurs would target the young and the old, 
while adults operating in pairs or "packs" could probably bring down healthy 
adults. Another possibility suggested in 'Predatory Dinsoaurs of the World' 
(Paul 1988) could have been a surprise attack in which an adult Tyrannosaur 
would rush out and severely wound a Triceratops with a bite and wait for it to 
bleed to death. I'm guessing even this scenario would have its risks, as a 
failed surprise attack could result in a T. rex running headlong into a set of 
horns. 
 
So on second thought, maybe a Triceratops, pound for pound, was MORE lethal 
than a T. rex.  
 
Sim Koning    
 
  

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> Date: Fri, 3 Dec 2010 00:06:14 -0200
> Subject: Re: Lack of Running Giant Theropod Tracks
> From: augustoharo@gmail.com
> To: simkoning@msn.com
> CC: martin.baeker@tu-bs.de; dinosaur@usc.edu
>
> 2010/12/2 Sim Koning :
> >
> > Adult tyrannosaurs, although slower, would have been able to kill 
> > ceratopsids and ankylosaurs, animals that the juveniles may have been too 
> > weak and blade-toothed to exploit. However, making a living by attacking 
> > something that is not only your own size, but also able to kill you as 
> > easily as you could kill it, may not have made for a very survivable 
> > lifestyle.
>
> This does not seem easy to infer. For example, the weaponry of a rat
> or squirrel (their incisors) make them probably very dangerous for a
> similarly sized predator, yet many weasels make a living mostly of
> eating these similarly sized rodents. If we only know the skeletons of
> the impala and cheetah, whe may think they were similarly armed and
> would expect the match to be even--a gracile version of the
> Triceratops-Tyrannosaurus duel. Yet, most of the time the cheetah is
> not harmed by this habitual prey (granted, their proportions suggests
> they were more engaged in running that fighting). Perhaps herbivores,
> because of being confronted intraspecifically less often than
> carnivores, are not as experienced (a carnivore in theory engages in
> conflict more often, each time it has to eat and there is no carrion
> around).