Dino size: go on, laugh at me

[Sue Blakey <ellensb@trib.com>]

Okay, guys, you can laugh at my stupidity on this one, but I need some 
help.
A second grader in Spain has requested the answer to this question: Why are 
dinosaurs so big?
She goes on to explain that she understands that they all are not, but she 
still wants to know why the big ones were so big. This information is for a 
class project, and I always try to come up with an understandable 
explanation and some reference I can refer kids or teachers to for more 
information. Not being a paleontologist by trade, I'm not sure I can answer 
this one. It sounds like a simple question, and those of you in 
biology/paleontology may have a very simple answer (other than the old 
wolf's rejoinder to Red Riding Hood, "the better to eat you with, my 
dear"). But I don't remember seeing this in my reference materials. 
(Granted, the new encyclopedia and other works everyone is promoting are 
not here yet; so I can't check those out.)
Where have I missed the answer to this one? What lecture did I sleep thr  
ough? Can anyone help?
Ellen Sue Blakey, Education Director
The Wyoming Dinosaur Center
ellensb@trib.com
phone: 307 864 3391
fax: 307 864 3882