Re: [BARYONYX]

[archosaur@usa.net]

owner-dinosaur@usc.edu wrote:
> 1: ANALOG
> 
> a: BEARS

I was never a big believer in the bear comparison. 
Question: Has it finally been proven beyond a shadow of a doubt that Baronyx's 
claw was on the hand.


> b: CROCODILES
> 
> Here you have elongate jaws, mostly carinate and occasionally serrated 
> conical teeth, but crocodile teeth variate along the jaws, and can be 
> large toward the back of the jaws, almost as large as the anterior 
> teeth---this is especially evident in the gharial, whose teeth are 
> nearly all the same size. Of fisher crocs, the forelimbs are used either 
> to walk with, or swim. Now, Baryonyx, hypothetically, could swim, and 
> definately could have walked, but the forelimbs were, most likely, not 
> used. As above, they were quite small.
 
Now we've run into a slight snag. Again when Baronyx was first found the first 
thing that popped into everyones head when they saw the jaw was that it looked 
very suchian. So of course everyone automatically (for some strange reason) 
assumed that it as a fish eater (of course the *lepidotes* remains in the 
stomach wer also a clue) Point is that most crocs are not fish eaters. Sure 
they live in a habitat frequented by fish, but for most fish makes up a small 
part of the diet. The obvious exception to this is of course the gharials and 
the false gharials. They are specifically designed to eat fish and only fish 
(and as far as I know, that's all they do eat.) Other crocs like niles' and 
indopacific crocodiles have a diet consisting of any animal that comes to 
drink. They prefer terrestrial animals. So why does everyone assume that since 
Baronyx was crocodile like, that it was a pure fish eater. If it was anything 
like modern crocs then it would most assuredly prefer land animals.

> Crocodiles, unlike bears, are developed almost to the exclusion of all 
> other forms of habitat, to the water, while bears are very varied in 
> their place of residence (though all species are excellent swimmers).
 
Modern crocs are, but lets not forget that the crocodylatarsia were quite 
divers in their day. Even today crocs are known to make long voyages to other 
water holes. I say that modern crocs are more developed to tackling prey from 
the water, than to just a simple watery existence.




> 2: HABITAT
> 
> A developed shoreline, riverbank, or lakeshore as opposed to the 
> estuarine or marine habitats gave *Baryonyx* a decided position within 
> which to exploit. Of his neighbors, *Megalosaurus* is too incomplete to 
> hypothesize about, and *Eustreptospondylus* was seemingly more suited 
> for fully terrestrial habitat.
> 
> When you're a shoreline animal, you develop certain traits, including 
> the swimming ability (the isolated ora or Komodo dragon, *Varanus*, 
> could also swim, but was delegated to a forest habitat, with occasional 
> forays to the sea to hop the next ride to the other islands it is now 
> found on), and a predisposition to aquatic or near-aquatic dietary 
> habits (i.e., feeding on those who feed on aquatic fauna or flora, 
> though we can probably say with some certainty that *Baryonyx* did not 
> eat leaves).
 
It sounds to me like Baronyx was designed to take animals down from a 
riverbank. Perhaps Baronyx was the dinosaur equivelant of a crocodile (even 
though deinosuchus should take that cake) or was in competition with crocs as 
shoreline hunters.


> 3: THE NOSE
> 
> The snout of *Baryonyx*, though often cited as similar to the crocodile 
> snout, is actually a near miss for such an analog, as based on several 
> features:
> 
> i)   external naris located back from tip, top, and back of snout
> ii)  orbits located laterally, with some binocular vision
> iii) teeth reduced in size towards rear of jaw
> iv)  anterior teeth forming "piercing" apparatus actually analagous to 
>      a bear-trap*
> 
> * = a bear trap functions by setting long blades into the flesh, 
> gripping and holding to prevent escape; such was a structure of the 
> *Baryonyx* jaws, though true function may be somewhat different.
> 
> Okay, so Bary could grab food, and prevent it from getting away, and 
> instead of doing this by holding it with the hands, as would many other 
> theropods, he could use the jaws instead, and so they were rather large 
> and strong. But the fish of the Wealden, for instance, didn't get very 
> large, as seen in *Lepidotes*, one of the rare occurances where we know 
> _for sure_ a meal (not diet) of a dinosaur.
 
More reason to assume the shoreline hunter theory. If only 
that damn claw would fit in somewhere.



> The snout with the posteriorly-displaced nares could mean that Bary 
> could probe the waters without having to splash around a lot and lunging 
> after leaping dinner, like certain ursines. This snout, like the kiwi or 
> platypus (you heard me, _platypus_!) could function as a probe for muddy 
> water or even the muck itself, meaning the food was like the mudskipper, 
> oir catfish, who bury themselves, or other aquatic life. The only 
> problem with this is that kiwi's and platypi have nares at the tips of 
> the their snouts, platypi being able to seal these off.
> 

I'm suprised that you didn't site cranes and other wading bierds who quietly 
probe the bottom of river banks and mudwallows for fish.


> 4: THE CLAW
> 
> Unlike raptor claws, the thumb ungual is broad, not compressed, and 
> would actually serve as a piercer or grabber than as a blade, for it 
> lacks any similarity to slashing blades, as used today or seen in some 
> modern animals (certain birds can and will attack by slashing with their 
> talons, instead of grabbing, by penetrating and digging in, tearing 
> flesh or just raking it painfully, and this is usually defensive 
> behavior---sounds like *Baryonyx* could have used intrspecific combat or 
> feared larger predators, unlikely as the latter is as Bary could have 
> reached over forty feet in length).

The only thoughts that I could give to that claw is that maybe it too was used 
to keep a hold on prey. But then why doesn't Baronyx have large claws on all 
it's fingers. And are it's forearms long enough to reach past it's snout. 

Another thought is that it used the claw to help hold it's ground from a 
thrashing animal. But as you stated above the arms weren't long enough, plus 
that would dull the claw rather quickly. I'm lost as to what that claw could 
possibly have been used for. Maybe a part of the body soley dedicated to fish 
catching alone?

 
> Comments are welcome,
> 
> Jaime A. Headden

I enjoyed giving them.
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