Scientists have made an unusual discovery inside fossilised dinosaur droppings: a bird feather. These ancient droppings are 66 million years old. It is thought to have been left by a Tyrannosaur. The feather is exceptionally well preserved, which is a rare find. This gives scientists a direct look at the dinosaur's diet. The meal included a bird, as shown by the feather. This might help explain how some birds survived the mass extinction. These findings are detailed in a new scientific study. It offers a snapshot of a predator and its prey.