Jeholbaatar kielanae (Wang, Meng and Wang 2019; Early Cretaceous) is a tiny arboreal multituberculate that preserves the middle ear bones in articulation along with the surangular, a bone usually missing in placental mammals. This reversal to an earlier morphology evolved as a mutation that persisted in all multituberculates as the middle ear bones rode along with the sliding (rather than rotating) jaw movements, that would have interfered with the ear canal in other rodents. More details and diagrams below.

Shenshou lui (Bi et al. 2014; Oxfordian, earliest Late Jurassic) was described as a member of the early mammalian clade, Allotheria. The large reptile tree did not recover that clade. Rather Shenshou nests at the base of the multituberculates, arising from the rodents. Grasping hands and feet suggest Shenshou was arboreal. Click here for Glires skulls compared.

Vilevolodon diplomylos (Luo et al. 2017; Jurassic, 160 mya; Figs. 1–5) was originally considered a relative of the Jurassic porcupine, Maiopatagium and then the pre-mammal, Haramiyavia. Here flying squirrel mimic Vilevolodon nests with the Jurassic squirrel, Shenshou. According to Luo et al., tiny middle ear bones fail to develop here (Fig. 2). Rather these bones are displaced squamosals. This and ankle trait mininterpretations caused Meng et al. 2017 to consider Vilevolodon a pre-mammal.

No basal mammals or pre-mammals have the same tooth count with giant incisors seen in Vilevolodon. In the large reptile tree Vilevolodon has the opportunity to nest anywhere in the Tetrapoda and it nests within Rodentia. In many rodents the jaws are free to move on a sliding jaw joint supported by a complex sling of jaw muscles. That seems to be the case here, as well.

Many rodents with sliding jaws have flat-topped molars and pre-molars for grinding seeds and other plant materials. These taxa share a sliding jaw joint, but the teeth occlude precisely.

Meng et al. interpreted a primitive ankle joint (astragalus and calcaneum side-by-side) for Vilevolodon. Reexamination indicates a fairly typical rodent ankle here (astragalus on top of the calcaneum) simply lacking a large tuber for the calcaneum. This sort of ankle is also found in Daubentonia, the extant aye-aye and in the porcupine ancestor, Maiopatagium.

Arboroharamiya jenkinsi (Zheng et al. 2013; A. allinhopsoni Han et al. 2017; Middle Jurassic) was traditionally considered a euharamiyid (pre-mammal) glider known from two crushed but complete specimens. Here it nests with Carpolestes, a primate-like rodent.