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Re: Dino reputation 'is exaggerated'



I'm not trying to characterize Velociraptor (V.) as a
sauropod predator... your analysis of V.'s lifestyle
may (or may not) be entirely correct. However, note
that the diameter of a cow's neck is not that
different from a sauropod's... so the question should
be "can a velociraptor climb and kill a cow". };) 

I am trying to make a point about possible dromaeosaur
claw function (locomotive device as opposed to
resource acquisition weapon), relative to the
vulnerabilities of large sauropods, and I am willing
to use V. as a model.

It is concensus that sauros had good reason to make
their necks as light as possible. My hands-on
experience only includes cows, deer, alligators,
turtles, birds and rattlesnakes; however, I can report
that mammalian skin can be _much_ tougher, relative to
shear, than reptilian or bird skin. Perhaps sauro skin
was tougher than elephant hide, but I don't believe
that is a warranted assumption relative to the distal
portion of the neck, unless there is fossil data. 

It is also concensus that sauros had very high blood
pressure; high blood pressures imply rapid blood loss.
Also, the longnecked sauros may not have been capable
of rapid and drastic (ie, defensive) head and neck
motion. 

V.'s teeth were sharp, and 2-3 cm long; I conclude
that if perched on the distal end of the neck, even
the unlikely V. (or a swarm thereof) might well have
had the physical tools necessary to bring down a large
sauro. (Note again that I am NOT saying this was part
of V.'s behavioural repertoire.)

What has been missing (before Manning et al) is a
practical method of placing V. (or more to the point,
it's larger relatives) in the right spot; if the
sickle claw could function as a locomotive device
analgous to treeclimbing spikes, on a substrate of
sauropod, then a practical scenario begins to
coalesce. I personally prefer emphasis on the
climbing/propulsive aspect of claw function, feeling
that "sticking" functions were mostly relegated to the
front claws and teeth (could dromaeosaurs "lock" their
jaws like a bulldog?)... greatly looking forward to
the coming exspansion paper.

--- Jorge Dichenberg <jorgedich@yahoo.com> wrote:

> --- don ohmes <d_ohmes@yahoo.com> wrote:
>  
> > Seriously, sauropods were slow, weren't they? And
> if
> > Velociraptors could climb trees, why couldn't they
> > climb a startled sauropod? 
> 
> Imagine a cat trying to climb a cow and kill it.
> Improbable, isn't it? 
> 
> I was simulated and looked at skeleton of
> Velociraptor. 
> There exists a living mammal matching amlmost all
> adaptations of it. It has big eyes, long skull,
> small
> sharp teeth, carries it's head forward, has big
> claws
> (although on foreleges, not hindlegs), long body,
> shortened legs and long tail which can be pointed
> vertically. It is predator, very active, lives in
> groups in sandy semi-deserts. 
> 
> This description fits, surprisingly, a meerkat.
> Small
> predator adapted to running in dense vegetation,
> digging and climbing. Claws are used for digging and
> climbing. Even combination of shortish legs and tail
> which can be pointed upwards fits - it is used by
> meerkats to keep visual contact in thick vegetation.
> 
> 
> Pack of meerkats can be fierce. But they typically
> hunt animals much smaller than their size. 
> 
> In contrast, Velociraptor has adaptations
> contradictory to modern big predatory mammals (ones
> that hunt animals bigger than themselves). Big claw
> is
> not supported by thick leg bones needed to withstand
> forces when fighting prey. Modern big cats and polar
> bears have much thicker legs and jaws. Velociraptor
> has thin bones and elongated skull - not suitable
> for
> wrestling. Head facing forward makes no sense in
> animal confronting prey much higher than itself.
> Legs
> are shortened which is not a good adaptation for
> fast
> running or jumping. Extremely long tail would be
> very
> vulnerable to breaking or indeed, biting by prey.  
> 
> In short, it was a small predator, not a big one.
> For
> Velociraptor, peaceful Dinotopia is better than
> violent Jurassic Park. ;)
> 
> J.
> 
> 
> 
>       
>               
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