Rattrap Production’s .45 Adventures has an excellent supplement called “Valley of the Thunder Lizard”, filled with dinosaurs, dino-men, Neanderthals and other Lost World fodder. It’s definitely my favourite 45A supplement, and it sees a lot of use in our 45A games.
Rich (the 45A creator) gives guidelines for creating your own dinos & variations in Thunder Lizard, as he’s obviously unable to include every single prehistoric beast in one book. Using his suggestions, and cribbing freely from his existing dinosaur stats, I’ve done up stats for a Styracosaurus, a Triceratops-like herbivore noted for the many-horned neck frill it sports.
My 45A Styracosaurus stats in PDF are free to download & use. Enjoy!