RE: Lack of Running Giant Theropod Tracks

[Sim Koning <simkoning@msn.com>]

Augusto Haro Wrote:
 
>I fact, I think I remember reading (or seeing in a
> documentary) about the fragility of the beak in Triceratops, and that
> sinking the horns into a predator may put the fragile snout close to
> the body of the predator, making it easy for the snout to be broken
 
That was shown on the 'Truth About Killer Dinosaurs' in which they fixed a 
plaster(?) head to a steel pole and rammed it into an object at 15 mph. Bone, 
while brittle, has some degree of elasticity, so I'm a little skeptical of 
their example. That aside, the real problem is that they mounted it to a solid 
metal pole rather than a flexible neck. Yet another problem is that in life the 
horns may have been driven into the underbelly of a T. rex rather than the 
flank so the snout may not have directly impacted the body at all. 
 
>I do not know. I think it may be more like an antelope than a pig in
> the lenght of the horns. I think an animal with straight horns has to
> attack by running at the predator
 
  The reason I use boars as analogs has more to do with the lethality of their 
tusks, which are long and sharp enough to kill adult lions. I dislike drawing 
too many potentially weak analogies between dinosaurs and modern animals 
(though it's hard not to do), so I rather focus on the horn lengths of a 
Triceratops and whether or not they were sufficiently long enough to deliver a 
fatal blow, which they almost certainly were. As far as their speed is 
concerned, I would guess that if a crocodile can gallop despite only having a 
semi-erect posture, than I would imagine it's not inconceivable that 
ceratopsians could gallop at almost rhino like speeds.  
 
  Considering the massive firepower of a Tyrannosaurs jaws and their ability to 
*bite ceratopsian horns off* I'm pretty sure a solitary T. rex could kill a 
Triceratops, albeit probably with a high degree of risk. However, the benefit 
of working together in pairs or in small groups would have been enormous when 
attacking both Ankylosaurs and Triceratops due to the largely unidirectional 
nature of their defensive weaponry; this would have had the added benefit of 
compensating for the Tyrannosaurs relatively slow turning rate. I feel that 
Phil Currie's discovery of 22(?) Albertosaurs together in one site further 
supports this possibility. Though if I had to guess (emphasis on guess) I would 
say that in the case of a tyrannosaurid species as large as T. rex that 
reproducing adults may have been limited to monogamous pairs with very large 
territories like modern birds of prey.
 
I apologize for the ad nauseam quality of the last section. It's reiterated 
simply for the sake of clarity.   
 
 
Simeon Koning
 


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> Date: Fri, 3 Dec 2010 11:23:29 -0200
> From: augustoharo@gmail.com
> To: simkoning@msn.com
> CC: dinosaur@usc.edu
> Subject: Re: Lack of Running Giant Theropod Tracks
>
> 2010/12/3 Sim Koning :
> >
> > 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).
>
> May be... I wonder if someone with more knowledge than me can tell
> about the latter developments on the feeding behaviour of
> ceratopsians... In our age of FEA, perhaps someone may take cards on
> the issue. I fact, I think I remember reading (or seeing in a
> documentary) about the fragility of the beak in Triceratops, and that
> sinking the horns into a predator may put the fragile snout close to
> the body of the predator, making it easy for the snout to be broken.
>
> > So on second thought, maybe a Triceratops, pound for pound, was MORE lethal 
> > than a T. rex.
> >
> I do not know. I think it may be more like an antelope than a pig in
> the lenght of the horns. I think an animal with straight horns has to
> attack by running at the predator, with the problem mentioned above.
> If an animal needs to use the horns at close range, having the horns
> curved, to align the point with the sirection given by the circular
> movements of the head, seems a better configuration, as found in
> bovids (yet even then, gnus commonly fall prey of nearly-sized
> predators), of the curved tusks of pigs. On the other hand, I do not
> know how much good were ceratopsians at running, for even when their
> limbs are strong, their different lenght, coupled with the unknown
> degree to which the scapula moved onto the sternum, seem to make the
> affair uncertain.