Here, a cimolodont multituberculate (possibly Ectypodus musculus) is eating purported competitor, a rodent. There is evidence that some multituberculates had omnivorous habits and could scavenge, so it makes sense that they could tackle other mammals; a SVP 2016 abstract even claims that there were some mainly carnivorous species.
Obviously, this is karmic irony. Rodents are suspected to have outcompeted multituberculates at least in North America, so seeing a cimolodont eating a rodent is a brief, spiteful jab.
This is amazing, oh my gosh. I love the details, the colouring and they anatomy! Keep up the good work!