Sexually dimorphic features are found in Angonisaurus which include presence or absence of tusks and difference is size and robustness of the temporal arch and the rostral.

Because of the lack of good lithostratigraphic marker beds, biostratigraphy has proven to be the most reliable aid for stratigraphic subdivision of this Lower–Middle Triassic succession.

Kannemeyeriiform dicynodont are characterized by the following combination of characters: skull tall; caniniform process triangular in lateral view; tusks absent; interorbital skull roof wide; preparietal absent; pineal foramen located at the base of a deep, conical pit; no strong break in slope between the interorbital skull roof and the intertemporal bar; postorbitals do not extend the entire length of the intertemporal bar and do not contact the squamosals posteriorly; parietals have broad exposure on the dorsal surface of the intertemporal bar; midline groove with raised edges present on dorsal surface of parietals for at least part of the length of the intertemporal bar; interparietal makes a moderate contribution to the posterior end of the intertemporal bar and meets the parietal along an interdigitated suture; occiput broad; temporal fenestra roughly rectangular in shape; margins of squamosal robust and thickened; fossa for the origin of the M. adductor mandibulae externus lateralis relatively vertically oriented; median wall of posterior dentary sulcus raised and thickened.

[6] Identification was based on a number of characters shared by the South African specimens and the holotype of Angonisaurus cruickshanki, including the broad occipital bone; robust squamosal; interparietal contribution to the skull roof; postorbitals that do not contact the squamosals on the skull roof, such that the parietals form a significant portion of the temporal bar; pineal foramen located within a deep conical depression; wide interorbital bar; and the triangular, tuskless caniniform process.

Food was processed by the retraction of the lower jaw when the mouth closed, producing a powerful shearing action, which would have enabled dicynodonts to cope with tough plant material.