The Biggest Dinosaurs

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

At 2:01 PM, August 20, 1997, Christy Nadalin wrote (in part):

<does anyone have any thoughts about why dinosaurs in Patagonia were   
growing so large during the Cretaceous>?

If I may expand upon Christy's question for the purposes of this   
discussion, does anyone have any thoughts about why the upper absolute   
size of dinosaurs was so much greater than the upper absolute size of   
terrestrial animals today?  Over the past 5 years or so, I have been   
(rather informally, I admit--no claim to scientific rigor on this one)   
compiling references on size estimates of predatory dinosaurs and their   
probable prey and comparing that relationship to the known sizes of   
extant terrestrial predators and prey.  From the material I've   
gathered--which is admittedly sketchy--the *relative* size of predators   
to prey in those two communities seem to be quite similar, even though   
the absolute sizes are quite different.

Pat Norton