Fish swallowing another fish is evidence of very rapid burial. Fossils have been found eating their last supper preserved in stone (a fossil) as physical evidence of a sudden burial. The fine sediments are evidence that this was executed by massive waters from a great flood. Other evidence has found dinosaurs engaged in battle. Other dinosaurs have been mummified with such detail that the contents of the food in their stomachs was preserved and under an electronic microscope the details of undigested proteins are apparent.
https://answersingenesis.org/fossils/how-are-fossils-formed/lessons-learned-from-a-fossil/
https://answersingenesis.org/fossils/how-are-fossils-formed/do-fossils-show-signs-of-rapid-burial/
