Re: dino-lice

[Jason Brougham <jaseb@amnh.org>]

> 
> On Apr 22, 2011, at 1:12 PM, Anthony Docimo wrote:
> 
>> 
>>  
>> 
>> > > I'm convinced that the forelimbs of alvarezsaurids were used for
>> > > *something*, and that *something* was associated with diet. After
>> > > all, the forelimbs weren't THAT small. Reduced though they were, they
>> > > certainly extended well beyond the body wall. Plus, the arms were
>> > > operated by a powerful musculature. I'm just not convinced the
>> > > forelimbs were used for digging into termite-mounds or ant-nests.
>> > > 
>> > 
>> > Can you name one extant vertebrate that has undergone an extreme reduction 
>> > of a limb or any other body part in its evolutionary lineage, in which 
>> > that body part played an important role in feeding?
>>  
>>  you mean like how the feet and teeth of sauropods kept getting simper and 
>> more basic, even while the rest of the body got bigger and bigger to eat 
>> more?
> 
> I said extreme reduction, meaning in size, from the ancestral state. I don't 
> think sauropod feet are so much smaller than prosauropod feet. No, I don't 
> mean like that, as I don't think anyone has suggested a locomotory function 
> for alvarezsaur arms. I don't think any sauropods are edentulous, but some 
> animals of course are, and this indicates that their teeth stopped being 
> important in feeding. 
> 
> Others on DML have suggested that alvarezsaur pectoral limbs reduced in size 
> to 4cm because they needed to perform some very small-scale  handiwork in 
> order to feed. I asked for an example of that in an extant animal.
> 
>>  
>> > In other words, when a lineage of animals undergoes extreme reduction in a 
>> > body part, isn't that body part usually becoming LESS pivotal in survival 
>> > rather than more?
>>  
>>  has anyone figured out what Oviraptors were eating with their two teeth?
> 
> Extant, please.
> 
>>  
>>  
>> > It is also possible that the human tailbone was used to tear open termite 
>> > mounds, as it projects as far from the sacrum as alvarezsaurid arms 
>> > projected from their sterna. The humans just sat on the termite mounds, 
>> > and their coccyx tips probed for openings, then flaked off the concrete - 
>> > hard matrix, 
>>  
>> and when alvarezsaurs were alive, were termite mounds concrete-hard yet?  
>> (did you already answer that?  if you did, i missed it)
> 
> I'm not a paleoentomologist, but I'm also not the guy who compared 
> alvarezsaur olecranons to those of modern anteaters. If mesozoic termite 
> mounds were soft, then why did alvarezsaurs need anteater - like olecranons? 
> If they were hard, the why did they need 4cm pectoral limbs instead of full - 
> sized ones like anteaters?
>>  
> 
> Jason Brougham
> Senior Principal Preparator
> American Museum of Natural History
> jaseb@amnh.org
> (212) 496 3544
> 
> 

Jason Brougham
Senior Principal Preparator
American Museum of Natural History
jaseb@amnh.org
(212) 496 3544