Every few years we get rewarded with a new dinosaur described from the Lance/Hell Creek Formations. In this crazy year we finally have one. Finally an Alvarezsauridae has been described from the Hell Creek Formation: Trierarchuncus prairiensis.
Sorry its paywalled cannot make comments
https://www.sciencedirect.com/science/article/pii/S0195667120302469
Here is some info on this very different dinosaur, one of my favorites, including some of my material so you can see what the paper is describing. Far better than what you see in the paper