===+======================+====================+==================== | | TOXODONT, NESODON | DIPROTODON ---+----------------------+--------------------+-------------------- 1 | Upper tush |Inc. 1 reduced | Inc. 1 tush | |Inc. 2 caniniform | | | tush | Inc. 2 reduced ---+----------------------+--------------------+-------------------- 2 | Upper molars | Rhinoceros-like | Bilophodont | | | | | | ---+----------------------+--------------------+-------------------- 3 | Lower tush | Inc. 3 | Inc. 1 ---+----------------------+--------------------+-------------------- 4 | Lower molars | Bicrescentric | Bilophodont | | | | | | ---+----------------------+--------------------+-------------------- 5 | Nasal opening | Over incisors | Over diastema ---+----------------------+--------------------+-------------------- 6 | Basicranial axis |Plane of base of |Plane of base of | | cranium parallel | cranium parallel | | with plane of | with plane of | | palate | palate ---+----------------------+--------------------+-------------------- 7 | Pterygoids | Pterygoids normal | Pterygoids normal | | | | | | | | | | | | ---+----------------------+--------------------+-------------------- 8 | Jugal |Takes no part on |Extends to | | glenoid fossa | glenoid fossa ---+----------------------+--------------------+-------------------- 9 | Post-tympanic process|Surrounds meatus |Not surround meatus | of squamosum | and crowds | nor crowd | | out tympanic | out tympanic ---+----------------------+--------------------+-------------------- 10 | Tympanic bulla |Large, inflated, | | | hollow | ---+----------------------+--------------------+-------------------- 11 | Palatine bones |Wide in front, | | | narrowing | | | somewhat | ---+----------------------+--------------------+-------------------- 12 | Premaxilla |Makes front of | Fused to maxilla | | palate | | | |