Premaxillae forming narrow dorsal keel along midline bearing 5 teeth each; last premaxillary tooth at premaxillary-maxillary suture; posterior maxillary process following jugal over entire length and terminating at the level of last dentary tooth; jugal long, low; anterior margin of dentary forming a beak; mandibular symphysis short, expanded to level of dentary tooth four; dentary with 18 teeth per ramus; last dentary teeth more prominent than last maxillary teeth; retroarticular process short relative to jaw length; atlas-axis-complex short and high, ventrally bearing prominent sagittal crest; anterior cervical vertebrae shorter than high.

Latin australis, southern; refers to the southern continent Australia