Re: About abelisaurs

[Eric Allen <erallen@yahoo.com>]

Just some of my random speculations:
Slender, "weakly built" jaws might not necessairly
mean they were not used to attack.  Big strong jaws
would be necessary if a predator wanted to grab its
prey in its mouth and not let go (i.e. crocodiles,
maybe _T. rex_).  Slender jaws would be fine if the
predator was only rushing it and biting off pieces of
flesh without "latching on" to its prey.  To use your
own comparison--like a pirrannah. A pirrannah rushes
in and removes a mouthfull of flesh.  A Carnotaurus
might have rushed in and bit off a chunk of
meat,repeated if necessary, then waited for the victim
to die from blood loss and shock (a school of
pirrannah-like carnotauri?).   
Jumping would be an option, but I'd want to
investigate the hindlimbs and spine in more depth to
see if they could have generated the power necessary
and/or be able to withstand the stress of such a
pounce (in any case, jumping to attack the neck or
flank of a fully-grown sauropod seems awfly risky--and
predators tend to prefer an easy meal)

Maybe they were scavengers...  ;)

We should probably establish that any hunting or
feeding strategy for carnotaurus may not necessairly
be indicative of abelisaurs as a whole.  Just a wild
guess here, but wouldn't carnotaurus's puny arms be a
more "derived' characteristic?  

Eric Allen
Undergraduate, TTU

--- Amtoine Grant <ajgrant@eastlink.ca> wrote:

> As I'm trying to figure out the likely methods of
> attack various 
> lineages of theropods may have used, I find myself
> contemplating on the 
> the abelisaurs. I've read that the lower jaw of at
> least Carnotaurus 
> seems 'weakly' built with more slender than usual
> teeth. To me, it 
> would seem that the jaws may not have been the best
> method of attack. 
> But the arms are atrophied as if attempting to make
> a two-legged snake. 
> .
> Which brings me to the feet. Noting the strange
> structure of the 
> foremost caudal vertebra, perhaps this may have been
>  an adaptation to 
> balancing on the tail while striking with the toe
> claws. . Are toe 
> claws known for abelisaurs?
> I was originally thinking that they may have been
> leapers, leaping and 
> ripping at the fleshy necks of sauropods, a feat for
> which they would 
> not have needed particularly strong jaws. Perhaps
> the 'wing'-shaped 
> dorsal vertebrae were an adaptation for withstanding
> the stress to the 
> backbone when landing from these leaps. .
> Also, I've noticed that the cranial morphology of 
> abelisaurs(Carnotaurus at least), compared to all
> other predators in 
> the animal kingdom, most closely resembles
> piranhas[albeit 
> superficially]. .
> Thoughts?
> 
> BTW, watching the Alpha's Egg episode of Dinosaur
> Planet, did anyone 
> else notice that they had Carcharodontosaurs
> attacking the sauropods in 
> South America? Last I checked, Carcharodontosaurus
> is from Africa, 
> Giganotosaurus is from South America. LOL
> 
> 



                
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