T rex carinae

["Norton, Patrick" <Patrick.Norton@state.me.us>]

Many thanks to those who reponded to my question about carinae on T. rex   
teeth. I also recall reading a paper a few years back--I think in the SVP   
journal--on bifurcated serration carinae in tyrannosaurid teeth (carinae   
that formed sort of an upside down "Y" on the tooth.)  As I recall, a   
significant percent of the tyrannosaurid teeth studied by the author   
exhibited that characteristic.

It would be interesting to know what was going on with tyrannosaurid   
carinae.  If the location of carinae varied along the vertical axis of   
tyrannosaurid teeth and they were regularly doing other odd things like   
bifurcating, is it possible that carinae were simply subject to less   
selection pressure in tyrannosaurids than in smaller theropods with more   
blade-like teeth?  It seems that serrations would be more useful on a   
weapon shaped like a knife than one shaped like a large railroad spike.