"Friis has come to believe, however, that the disappearance of the dinosaurs was not even the most interesting development of the Cretaceous period. She is more interested in a pair of easy-to-miss boulders near the feet of the T. rex, which bear impressions of some very old angiosperm leaves."

https://www.newyorker.com/science/elements/the-fossil-flowers-that-rewrote-the-history-of-life