You heard it here first.
Birlenbach and Fox 2018 found similarity in the rodent, multituberculate (Fig. 1) and plesiadapiform teeth. In the large reptile tree (LRT, 1038 taxa, subset Fig. 2) that is so because they are closely related to one another.
Figure 1. Animation of the mandible of the multituberculate Kryptobaatar showing the sliding of the jaw joint producing separate biting and grinding actions, just like rodents, their closest relatives in the LRT.
Unfortunately
Birlenback and Fox are working from older, smaller and less complete charts that tells them these three taxa are not closely related.
Figure 2. Subset of the LRT focusing on Glires, rodents and multituberculates.
References
Birlenbach DM and Fox DL 2018. Morphological similarity in the dentition of rodents, multituberculates and plesiadapiformes during the Late Paleocene in North America.
The Pterosaur Heresies 