Re: the mystery of the furcula

[StephanPickering@cs.com]

DinoGeorge is, indeed, correct. Clifford A. Hui has published an excellent overview of the furcula in avialian theropods:
2002. Avian furcula morphology may indicate relationships of flight requirements among birds, Jour. Morphology 251:284-293. I would suggest the individual who criticized DinoGeorge to, at least, familiarize himself with avian literature, as the function of the furcula (the wishbone) has never been in doubt:  it is fused clavicles. I recommend quite highly for every paleontological library: J.J. Baumel, A.S. King, J.E. Breazile, H.E. Evans, J.C. Vanden Berge, eds., 1993, the second edition of Handbook of avian anatomy: nomina anatomica avium. There J.J. Baumel and Larry Witmer, pp. 45-132, have a paper, "Osteologia", which
provides an excellent overview. As Clifford correctly observes, when the furcula shape is changed from being straight to cranially curved, force vectors of anterior sternobrachialis on the wing are also altered. K.P. Dial in 1992, Auk 109:874-885, has an interesting discussion, "Avian forelimb muscles and nonsteady flight: can birds fly without using the muscles in their wings?". All of this is of interest when one begins examining the furcula of non-flying theropods, where the function of the furcula needs to be explored.  Walter Bock's form-function complex (developed with Gerd von Wahlert in the 1960s) would be a good foundation. I think it would be of interest if an enterprising dinosaurologist conducted free-body force analysis of bone-muscle systems of, say, an allosaur.