Re: [Re: Suchomimus vs Baryonyx: Dare to Compare]

[archosaur@usa.net]

The following quotes come from Tracy and M.Alan

> I have always thought the bear analogy strange.  Quoting Greg Paul (who

> makes a very good point here)"no living land animal as gigantic as

> spinosaurs survive on fresh-water fish alone.  Even brown bears d so

> only during the brief and intense salmon runs through narrow mountain

> streams..."

> [Predatory Dinosaurs of the World, p.271]

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Agreed, the bear analogy never made any sense to me either


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> 

> > using it's large thumb claw. Why? When the head has a longer reach,

> > the claw would be

> > inefective. Then it caught fish with his mouth.

> 

> yes, the crocodile analogy sounds more logical - crocodiles of course

> grew to spinosaur size.  However the metabolism is different - crocs are

> ectotherms, whereas spinosaurs like other theropods would have probably

> been quasi-endothermic adults (and fully endothermic during the rapid

> growth phase when young).

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Eh, I'd be careful with this one. If we're going to throw the metabolic weight
around then lets not forget that in this sense, crocodylians are not
ectotherms but gigantic homeotherms and thus would fit in the
quasi-endothermic position. 

Nor are crocodylians pure fish eaters. Only a couple like _G.gangeticus_
_T.schlegelii_ and _C.cataphractus_ are true fish eater, although
_C.cataphractus_ has the potential to take down slightly larger prey.

So spinosaurian and crocodylian metabolism would equal out, well as long as we
use the right crocodylians.

And as for baby crocs, having to eat 5% of ones birthrate everyday, doesn't
exactly fit the traditional ectotherm perspective.

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> In fact, all crocodile anologues - phytosaurs, champsosaurs,

> cochleosaurs, eryopids, etc were *all* ectothermic

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Gigantotherms in some cases

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> > Lets examine this. We have to play the picture all the way through.

> > Sure

> > it has a skull that looks similar to that of a ghavial. But the

> > nostrals

> > are still on the side of the skull and not the top,

> 

> which *does* seem to mitigate against a semi-aquatic life-style

> 

> > so it didn't float like a ghavial. It couldn't swim like a ghavial.

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True, but the snout would still perform the same job as that of a gharial's;
to sweep fast across water, and the teeth (from what I've seen) look very
similar to plesiosaur teeth in needle like design, always good for a quick
spearing (this basis is from the abcnews closeup profile of the skull).

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> > The whole body

> > ungulates, not just the tail. So we rule out swimming to catch a fish

> > (it would have to have been a deep river, lake, to begin with). So it

> > stood up to it's belly in a river. The rivers bottom would have to

> > have

> > been hard or it would have sunk into the mud. IT would have to have

> > fast

> > reflexes to catch the fish. The water would have to have been clear

> > for

> > it to see the fish. A 6 foot fish swiming in 6 feet of water is

> > awfully

> > shallow for it. The biggest fish usually are at the deepest part of

> > the

> > lake/river.

> >

> > So I say no fish eater. What did it eat then? Terrestrial animals of

> > course.

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Well ok, but how does one get past the jaw dilemma with Suchomimus? Those jaws
are just too darn slender to withstand the force of a freaked out deinosaur, a
large one that is.

I could see the jaws being used in hunting smaller animals, but when it comes
to animals like iguanodonts, all I can imagine is a Suchomimus with a
shattered jaw.

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> *but* then why the elongated snout and conical (fish-eater) teeth?The

> whole beast is an enigma!

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And I thought segnosaurs were a pain to describe :)

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> [snip]

> 

> > I can't see Torvosaurs being close to Spinosaurs.

> 

> certainly the accepted paradigm is that the Spinsoaurs are cousins to

> teh Megalosaurs (Torvosaurs).  But accepted paradigms have been wrong

> before...

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Like that whole, deinosaurs are slow, dimwitted evolutionary throwbacks
paradigm. 
 

Archosaur J


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