Ideas for Short Dinosaur Presentation

[Dino Guy Ralph <dinoguyralph@gmail.com>]

If you were going to put together a brief presentation on dinosaurs for a 
general audience, what would be the main topics that you would want to cover?  
I'm talking about a fun little enrichment talk for high school or college level 
students, with just a handful of topics.  The idea is to cover the basics of 
dinosaur science rather than to devote the talk to a particular specialization 
("Histology of an unidentifiable ornithischian bone fragment and its 
implications for reconstructing the Maastrichtian paleoecology of Australia " 
-- not).     

What topics would you include in a brief talk on the history of life on earth?  
(Let's see just how fast this Wayback machine can go -- no time for the boring 
stuff)!  

---Ralph