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Re: other challenges

<<I guess I should now concentrate on some of Martin's challenges
(e.g., semilunate perhaps not strictly homologous in birds and theropods?; etc.), and Ruben's more recent challenge about the lungs (hepatic piston and all that).>>

Martin's (1991; I think) argument about the semilunate appears to be the same as published by Tarsitano (1991; and I think Tarsitano and Hecht, 1980); a juvenile _Deinonychus_ appears to exhibit fusion of two seperate carpi to form a semilunate, whereas the semilunate of birds is a single element. Of course, the value of this evidence is questionable, we need more specimens and a reinterpretation of the evidence.

Ostrom in his desriptions of _Deinonychus_ screwed up on identifying the indentity of the semilunate element, he saw it as a radiale which is a seperate element from the semilunate in avian wrists. Current thinking identifies the semilunate as D1 carpal.

Matt Troutman
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