"creeping" animals

[Accipiter <darwincr@laplaza.org>]

"Jura" (archosaur@usa.net) writes:

  >Truly an interesting question, but before 
  >one decides to pin this gigantism on
  >endothermy, let's also remember that 
  >140 million years of evolution has yet to
  >produce a bird that even comes in at a tonne, 
  >much less a multitonne one; and birds are 
  >twice as metabolically active as mammals. 

Sorry.  I forget.
What is the primary argument in support of the 
notion that dinosaurs were >not< endotherms?  
I have five high-school students camping out here,
so I'm not functioning at full capacity.  

Many thanks,

John C. McLoughlin