Birds are dinosaurs. Because the ancestors of all birds were dinosaurs, living birds still have many dinosaurian characters like feathers, three-fingered hands, modified wrist bones, and incubating eggs on nests. Birds (also referred to as avian dinosaurs by paleontologists) that lived alongside (non-avian) dinosaurs had even more dinosaurian features. Like teeth. Although all toothed birds went extinct with most of the other dinosaurs 66 million years ago, they were quite prevalent with several specimens making there home here in the Western Interior Seaway of Kansas.
Recently, science writer and book author Riley Black wrote a wonderful piece for Smithsonian Magazine on these fantastic toothed birds of the Cretaceous. Make sure you check out her article for more information (with comments from Fort Hays State University paleontologist Dr. Laura Wilson!).

Michael Hanson and Bhart-Anjan S. Bhullar/Nature Publishing Group