Well, if you'd read the article, those guys disagree with you.
"It was very exciting because we knew this was a type of animal that no one thought you'd find anywhere at any time in North America," said paleontologist Randall Irmis, a graduate student at UC Berkeley and lead author of the study which appears today in Science.
"It has shaken up the old theory," said Bill Parker, a paleontologist at Petrified Forest National Park who also studies dinosaurs. "Everything was nice and neat before."
Oh, let me guess, they aren't *real* scientists. Their opinion doesn't count.
The discovery means that dinosaurs didn't simply replace their ancestors. Instead, the two types of animals lived side-by-side and competed for resources for millions of years.
Then how did they differentiate enough to become two distinct species if they shared the same environment? The initial genetic changes should not have been enough to prevent inbreeding for several generations, at least. So how DID they differentiate?
Humans and dogs share the same environment. How did they differentiate?