Triceratops Skull

[sdhughes <sdhughes@ualberta.ca>]

I have recently attended a introductory University course on the evolution of 
Dinosaurs at the University of Alberta. The prof in this course told us that 
Paleontologists have relatively recently come up with theories about the 
Triceratops skull. The theory is that the extended back ridge of the skull was 
actually used for attachment of muscles for the jaw. As well as this muscle 
they believe that there was a large muscle behind the ridge to aid in lifting 
their massive skulls. This gives the Triceratops a more bull-like appearance. 
Is this a common theory?
 Thanks 
Shara