original: Extinction Non-avian dinosaurs suddenly became extinct approximately 65 million years ago.
simplifications: non birdlike dinosaurs suddenly died out about 65 million years ago. Non-avian dinosaurs disappeared 65 million years ago. Extinction: Non-avian dinosaurs became extinct about 65 million years ago. Extinction Non-avian dinosaurs suddenly died out about 65 million years ago. Flightless dinosaurs suddenly died out around 65 million years ago. Non-flying dinosaurs became extinct around 65 million years ago. Land dinosaurs suddenly became extinct approximately 65 million years ago. Non-flying dinosaurs quickly died off about 65 million years ago. Some of the dinosaurs were not related to birds. These dinosaurs suddenly became died out nearly 65 million years ago. Extinction Non-avian dinosaurs were suddenly extinct about 65 million years ago.