Great Plains Dinos

The vast plains of the American Midwest and West are home to the Prairie Digger, a social burrowing hysolophidont. Digger towns are a common occurence on the plains, where lookouts survey the grasslands for danger all day. The Prairie Digger's tusks harken back to its distant ancestor Heterodontosaurus, and while the female pouch is a more recent development. The Hysolophidont pouch evolved roughly ten million years ago in the more arctic species as a way to keep eggs and hatchlings warm during hiberation. Female hormones not only develop the pouch during her mating years, but limit the number of eggs available during each mating. Once all of her eggs are gone, the hormones shut down and "fill" the area around the pouch with fat to seal it off.
The Diggers' most common predator is the Tunnel Runner, a species of roadrunner. The most common predator of it, and practically anything else it can grab, is the Mojave Raptor. The Mojave Raptor's name is misleading because the species can be found anywhere on North America that isn't too cold or too barren. And even that might not stop it.

(Author's note: I am well aware that there are no dinosaurs with marsupial pouches. I made it up just for the sake of it. And once I made a roadruner species, complete with scientific name, I had to make a coyote analog. I really like those cartoons. Just be glad I thought of a better name than "Marathonicus supersonici" or something along those lines).