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Re: Velociraptor scavenged azhdarchid pterosaur



Well put - and to be honest, I'm not sure what the testing structure is to 
differentiate between the alternatives in this case.  The V-P event preserves 
two sets of similarly contradictory information: it shows rather irrefutable 
evidence of combat (supports predator hypothesis) but it also shows that the 
potential predator was undersized and getting mauled (weakens predator 
hypothesis).  Perhaps others on the list have thoughts about the appropriate 
hypothesis structure in this case.  Personally, I find myself at a bit of a 
loss.

--Mike

On Mar 4, 2012, at 12:39 PM, Dan Chure wrote:

> I agree with you that the superpredator model is too widely and wildly 
> applied.  However, the issue still is can the V-P predator event 
> hypothesis be tested?  If so, how and is there evidence to test it?  
> Similar might be said about competing hypotheses. There are always 
> alternative hypotheses, the trick is testing and choosing between them.
> 
> Dan
> 
> 
> On 3/4/2012 9:58 AM, Habib, Michael wrote:
>> On Mar 4, 2012, at 9:47 AM, Dan Chure wrote:
>> 
>>> While the failed nest raiding is possible, I don't see how it can be
>>> invoked if there wasn't a nest at the site.  I understand that there
>>> might have been a nest nearby that wasn't preserved but if you have no
>>> evidence that there was a nest where the V-P were found it makes no
>>> sense to build an interpretation around its being there.  The same
>>> general region preserving nests is not the same as a nest at the site.
>>> There are many Protoceratops found that are not on nests or a nesting
>>> sites.  So the lack of a nest might be taken as evidence, although maybe
>>> weak, that falsifies the nest raiding hypothesis.
>> I used to take that same perspective myself, actually.  I do agree that nest 
>> raiding cannot be supported as a specific hypothesis; I was using it more to 
>> make a point than anything else.  Without a nest preserved, I fully admit 
>> that it is speculation to claim nest raiding, specifically.  However, I 
>> think it still makes the point that there are other scenarios that could 
>> lead to the combat in question.  Why should we consider them?  Because the 
>> circumstances of the fossil should make us immediately skeptical of a 
>> predation hypothesis.  At the very least, we should be extremely skeptical 
>> that this was a typical or average event.
>> 
>> Look at this way: if the fossil in question preserved two extant taxa, in a 
>> similar situation and size ratio, we would be much more confident that the 
>> predator screwed up, at the very least.  For some reason, the strong 
>> preference bias for small, juvenile prey among even quite powerful modern 
>> predators doesn't get its due when we examine the terrestrial fossil record.
>> 
>> 
>>> The development of a slicing claw and the attendant morphologies seems
>>> to be an odd adaptation if V (and its relatives) regularly fed only on
>>> prey smaller than itself.
>> Why?  Most living terrestrial predators, including animals as powerfully 
>> armed as cats and birds of prey, hunt animals smaller than themselves.  Even 
>> if the claw as truly a slicing structure (and it might not have been, 
>> although it's certainly plausible), I don't see why that is incompatible 
>> with feeding on prey that is relatively large in ecological terms, but still 
>> smaller than the predator (say, for example, 50-66% the size of the 
>> dromeosaur).
>> 
>> I realize that I am going out on a limb a bit - my point is not that my 
>> speculative hypotheses here are necessarily better, but rather that the 
>> "super-predator" models so popular in paleontology have not received due 
>> skepticism.  If we can really, truly shore them up then that's great - but 
>> it should be recognized how extraordinary it would be to have a wide range 
>> of predators attacking prey much larger than themselves.
>> 
>> Cheers,
>> 
>> --Mike Habib
>> 
>> 
>> Michael Habib
>> Assistant Professor of Biology
>> Chatham University
>> Woodland Road, Pittsburgh PA  15232
>> Buhl Hall, Room 226A
>> mhabib@chatham.edu
>> (443) 280-0181
>> 
>> 
>> 
>> 
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>> 
>> 
> 
> 

Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181