Dinosaur Fossil Found in Mammal's Stomach (against evolution

Personally, I don’t find this at all surprising. It was theorized that mammals remained small till after the dinosaur die-off mainly because there was no data to suggest otherwise. A safe assumption to be surebut still, we’re talking about millions of years, and hey, they had to start getting large at some pointright? Could not this simply have been a brief experiment in size that leads nowhere? With that in mind, two questions come to my mind. Where did they come from and where did they go? That is to say, it will now be quite interesting to search for their evolutionary ancestors AND to look for a continuation of the lineageI think.