Mesocyon

 ( Hesperocyonines ) 

Mesocyon ("middle dog") is an extinct genus of the Hesperocyoninae subfamily of early native to North America. It lived from the Oligocene to Early Miocene, 30.3—20.3 Annum, existing for approximately . Mesocyon at fossilworks Fossils are known from Oregon, southern California and the northern Great Plains. It was roughly coyote-sized, and the first known canid to have a primarily meat-based diet.