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Re: Question: Why did birds lose their teeth?



It should probably be noted that, contrary to popular belief, wing claws are 
not restricted to Mesozoic birds and baby hoatzins. Many groups of modern birds 
retain wing claws at least on digit 1. 
http://scienceblogs.com/tetrapodzoology/2010/06/30/clubs-spurs-spikes-and-claws/

Crown birds are also not the only bird lineage to include toothless forms and 
clawless forms. Some toothed enantirornithians lost their claws, like 
Shanweiniao and Longirostravis. Some clawed Mesozoic birds lost their teeth, 
like Confuciusornis and Schizooura. There doesn't seem to be any solid 
correlation between tooth loss and claw loss among Mesozoic birds, and it's 
entirely possible the only durning bird group was toothless due to luck, or the 
enhanced ability for beaks to rapidly adapt to new niches and food sources 
compared to teeth.

Matt Martyniuk

> On Mar 11, 2014, at 4:47 AM, don ohmes <d_ohmes@yahoo.com> wrote:
> 
> 
> 
> Interesting question, and I hadn't thought to ask it -- it certainly wasn't 
> flight-related, though ;).
> 
> Accepting for the moment that a viable explanation for tooth loss in birds 
> must also explain turtles -- are clawless, but toothed turtles known? Is a 
> pattern of first claw loss, then tooth loss seen in turtles? Perhaps "modern" 
> land turtles are secondarily clawed? 
> 
> 
> ------------------------------
>> On Tue, Mar 11, 2014 2:08 AM EDT Dr Ronald Orenstein wrote:
>> 
>> In which case, why did turtles lose their teeth?
>> 
>> Ronald Orenstein 
>> 1825 Shady Creek Court
>> Mississauga, ON
>> Canada L5L 3W2
>> ronorenstein.blogspot.com
>> 
>>> On Mar 11, 2014, at 7:53 AM, Dann Pigdon <dannj@alphalink.com.au> wrote:
>>> 
>>> 
>>> On Tue, Mar 11th, 2014 at 9:41 AM, don ohmes <d_ohmes@yahoo.com> wrote:
>>> 
>>> 
>>> I do not claim this is testable (I have thought of one possible way, I will 
>>> mention it later),
>>> but a plausible selective path to tooth loss in birds is clear. 
>>> 
>>> Think about this next time you are flossing -- small bipeds that cannot use 
>>> their hands to clear
>>> stuck/snagged material from their mouths have a problem -- if they are 
>>> volant, the problem is
>>> exacerbated. 
>>> 
>>> Fully optimizing wings (in birds) for flight logically and apparently 
>>> demands losing the claws --
>>> and a toothy bird is just that more likely to die from something a little 
>>> too big to swallow, not
>>> to mention catching something too large in the first place! 
>>> 
>>> Perhaps there is a clear pattern in the data of 'first go the claws, then 
>>> the teeth'?
>>> 
>>> How often to extant non-volant reptiles try to clear their mouths with 
>>> their limbs?. I imagine it'd be 
>>> impossible for crocodilians, not to mention potentially limb-shredding for 
>>> monitor lizards. 
>>> 
>>> Many non-volant toothed theropods also had long necks and short forelimbs, 
>>> making any sort of 
>>> grooming of the mouth via the forelimbs unlikely (tyrannosaurs and 
>>> carnotaurus are obvious 
>>> examples).
>>> 
>>> -- 
>>> _____________________________________________________________
>>> 
>>> Dann Pigdon
>>> Spatial Data Analyst               Australian Dinosaurs
>>> Melbourne, Australia               http://home.alphalink.com.au/~dannj
>>> _____________________________________________________________
>>> 
>