1. The parietal bones fit between the frontal, the supraoccipital, the squamosal, and the lateral margin of the Alisphenoid

2. The posterior part of each Alisphenoid forms a triangular process which fits into the angle between the squamosal and the petrosal

3. Most paleontologists, however, still think that animals with the dentary-squamosal jaw joint and the sort of molars characteristic of modern mammals should formally be members of Mammalia.

4. Mesozoic synapsids that had evolved to the point of having a jaw joint composed of the dentary and squamosal bones are preserved in few good fossils, mainly because they were mostly smaller than rats: They were largely restricted to environments that are less likely to provide good fossils.

5. They included twelve genera and proposed five synapomorphies for the tribe: presence of a pair of mammae on the chest; a long palate marked by posterolateral palatal pits, perforations near the third molar; absence of an alisphenoid strut, which in some sigmodontines separates two foramina (openings) in the skull; absence of a suspensory process of the squamosal bone attached to the roof of the tympanic cavity, the tegmen tympani; and absence of a gall bladder.