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Re: semilunate carpal



>>The hypertrophy of the arms and hands could also be explained as selection
>for increased lever arm length and turning moments.<<

>You mean it's originally a flight-related character exapted for predation in
a "make-the-best-of-a-bad-thing" fashion?  Like George's BCF, I think this
is putting the cart before the horse.  The flight stroke developed from the
predatory stroke, not the other way round.<
 
I meant exactly what I said, which has nothing to do with BCF. 
 
I sense this thread is getting a bit tired, so I'll wrap up my role by adding that we could all benefit from more in-depth biomechanical studies of the maniraptoran wrist to provide some insight into these types of questions (if only we knew more about those wrists!). The "predatory stroke", at least as far as I'm aware, is no more or less than a  >hypothetical< explanation of the function of the semilunate carpal in the maniraptoran wrist.  Another hypothesis is that it was an adaptation for better orientational control among cursorial bipeds with aerodynamic surfaces on their arms. And there are others as well.  Whatever happened to the wrists of those creatures was certainly the resultant of a number of selection pressures.
PTN