Money:
Press [Shift] + 4 to get more money..

Change Dino-Poo Into Rocks:
Name an exhibit Copralite Corner, all dinosaur poo turns into rocks 
Change Dinosaur Egg Contents:
Name a scientist Dr. Frankenstein and there's a 10% chance an egg will change its contents when the scientist visits. 

Extra Money:
While you're playing in a game, press the Shift key + the 4 key ($) to get more money. 

Secret Unicorn:
When selecting exhibit name type Xanadu in its place. Unicorn will then appear in animal menu. 

Unlock All Dinos:
Just name a guest DINOMAN. 

Unlock Deinosuchus:
To unlock the Deinosuchus (a very large Jurassic alligator)just complete all the scenarios and after you complete the last one you will get a message saying you got it.