No 2 - - Triceratops of Wyoming

[2] Triceratops – Wyoming (1994) 
 

While not as awesome as stegosaurus, Wyoming has the second best official state dinosaur with the massive triceratops. At 12 tons and up to 9 metres in length, it was a badass monster with a massive skull (among the largest of all terrestrial animals) the largest of which is 2.5 metres in length, making the skull half the size of a stegosaurus - - and that’s just triceratops’ skull!)

Hailing from the Hell Creek formation, 38 skulls of this classic monster have helped make it one of the most famous and well-known dinosaurs of all. And believe it or not, back in the 1800s, the horns were initially believed to belong to a “large and unusual bison,” if you can believe it.

References:
http://en.wikipedia.org/wiki/Triceratops