The large animals, such as dinosaurs would have been preferentially eliminated while some of the small ancestors of present day mammals would have survived.
(The large animals, such as dinosaurs; would have been preferentially eliminated; T:while some of the small ancestors of present day mammals would have survived) (some of the small ancestors of present day mammals; would have survived; )
The large animals, such as dinosaurs some of the small ancestors of present day mammals
would have been preferentially eliminated would have survived
T:while some of the small ancestors of present day mammals would have survived