Tyrannosaurus errata

[Jeffrey Martz <martz@holly.ColoState.EDU>]

     I'm looking for whatever reference (if any) that Phil Currie has
puiblished his claim that pneumaticity in the skull of _T.rex_ may have
been useful for hearing low frequency sounds.  I would also like the ref
for the original study  that determined that the spacing of the ears in
mammals determines the frequency of sound they hear best; wide spacing =
lower frequency.  
    Ralph Molnars 1991 description of the skull of _T.rex_ mentions a
"sheet" formed from the quadratojugal and squamosal related to the
enlargement of the adductors.  Could someone elaborate on exactly what
the nature of this "sheet"?  One of the most interesting implications of
Molnar's study for me was the fact that the expansion of the rear part of
the skull which resulted in the forward facing eye sockets appears to be
the result of the enlargment of the jaw-closing adductors, something Alick
Walker apparently also noted in his 1964 Philosophical Transactions of the
Royal Society Paper on _Ornithosuchus_ and tyrannosaurs (although I
haven't read thatb one yet).  To me, this seems to have imporatant
implications about the actual presence of stereopsis in _T.rex_, although
I don't recall that Molnar actually suggested himself that the forward
oriented eyes might have been non-adaptive side effects of the enlarged
adductors.        
    Finally, can anyone recommend a good paper or book dealing with  
changes in reefs and reef building organisms through time?  

LN Jeff