[1] TTU P-11422, a partial juvenile skull, had also been referred to "P." scurriensis,[3] however Stocker (2013) found no basis for this referral as the specimens do not share any synapomorphies.

Furthermore, the Post Quarry which is within the stratigraphically higher Cooper Canyon Formation of the Dockum Group was recently demonstrated to be mid Norian (220–215 Ma).

Thus the most probable age for the Camp Springs Formation and the lower member of the Santa Rosa Sandstone is latest Carnian or early Norian.

Unlike all other phytosaurs, the basitubera, areas at the base of the skull in front of its attachment point with the neck, are widely separated mediolaterally.

Eight characters are shared by Wannia and all other phytosaurs (synapomorphies), including nares that are directed dorsally and the presence of separate ossification, the septomaxilla, anterior to the nasals and surrounded by the premaxilla.