The oldest known horned dinosaur in North America is called Zuniceratops. It lived 12 million years before [Michael] Ryan's find, and also had large horns.
That makes the newly found creature an intermediate between older forms with large horns and later small-horned relatives, said State of Utah paleontologist Jim Kirkland, who with Douglas Wolfe identified Zuniceratops in New Mexico in 1998. He predicted then that something like Ryan's find would turn up.
"Lo and behold, evolutionary theory actually works," he said.