RE: Regarding Spinosaurus

["no go" <honkietong@hotmail.com>]

> > If they were 'high metabolic' it is even more difficult (at least for me) 
> > to
imagine them as piscivores - how many big-bodied, freshwater, warm-blooded,
obligate fisheaters does anyone know of? (Some probably incorrect 
speculations
on why freshwaters tend to be dominated by big coldies can be found in ch7 
of my
book, for those of you sad enough to own a copy.)<<


I suppose a great deal of marine mammals like Orcas and some whales fit the 
bill quite well, hunting marine stuff that was typical of the fish-sized 
meal Spinosaurus might have gotten (eg. Sealion). As these animals are quite 
different from your land-based animal (not to mention they play by a 
different set of rules), trying to draw up anything here is not too 
appropriate. However, the general anatomy of the Spinosaurids suggest that 
these animals were more specialized for fish-hunting then your typical 
carnivorous dinosaur permutation. Not that they had to be obgilate 
piscivores, but just that they were well-adapted ones. Given a healthy 
supply of large fish, I suppose Spinosaurus, or any other large bodied 
animal could live soley on a diet of fish alone, irregardless of its 
metabolic rate.

But I doubt there's any question about Spinosaurus being able to hunt 
non-fish meals, the real question is, how effective was it at hunting in 
this niche beside other large predators that feed on land based animals? 
This question I believe, is the one that should be answered. Was Spinosaurus 
less adept at nailing a meal typical of what the other large predators that 
shared its' habitat might have gotten? Prehaps Spinosaurus only hunted small 
to medium sized animals despite its impressive size? And hence not competing 
too much with the other predatory dinosaurs of its' time?

Just for the record, I have no idea why Jack Horner thinks Spinosaurus was 
the "ultimate" predator though. On what justification I'd like to wonder? 
Save for the arms, Spinosaurus seems to fit far better into features he 
likes to claim for an obgilate scavenger, then a certain other dinosaur he 
likes to think of as being one...

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