TABLE 1. A summary of the arguments for and against slender longirostry in QM F42665 utilising the specimens referred to ‘U. willisi’ in Stein et al. (2016), prior to the taxonomic revisions made in this paper.
| Arguments for slender longirostry | Counterarguments | Arguments for brevirostry |
| Marked transverse constriction of the dentigerous portion of the mandible | Constriction is an artefact caused by a) damage to the mandible and b) articulation with a misaligned temporal fragment in the reconstructed skull | – |
| Proportionally shallow mandible indicates shallow skull correlated with slender longirostry | Uncrushed posterior cranial fragment QM F31075 has a proportionally deep occiput indicating cranial proportions closer to brevirostrine taxa. | – |
| Proportionally elongate retroarticular process | Relative length of retroarticular process is ambiguous | – |
| – | – | Proportionally small supratemporal fenestrae. |
| – | – | Blunt, molariform, posterior dentary teeth. |
TABLE 2. Late Oligocene crocodilian fossils discussed in this paper, their identifications in previous papers, and their identification in this paper.
| Specimen | Description | Identification in Willis 1997 |
Identification in Stein et al. 2016 |
Identification in this paper |
| QM F31060 | rostrum | Baru huberi (holotype) |
- | Ultrastenos huberi, probably the same individual as QM F31076. |
| QM F31061 | right premaxilla and incomplete right maxilla | Baru huberi (paratype) |
- | Ultrastenos huberi |
| QM F31062 | right premaxilla | Baru huberi (paratype) |
- | Baru wickeni |
| QM F31063 | right maxilla fragment | Baru huberi (paratype) |
- | Baru wickeni |
| QM F31064 | right maxilla fragment | Baru huberi (paratype) |
- | Ultrastenos huberi |
| QM F31068 | left dentary fragment | Baru huberi (paratype) |
- | Ultrastenos huberi |
| QM F31069 | symphyseal fragment of mandible | Baru huberi (paratype) |
Ultrastenos huberi | |
| QM F31075 | posterior cranial fragment | White Hunter Cranial Form 1 | Ultrastenos willisi | Ultrastenos huberi |
| QM F31076 | posterior cranial table | White Hunter Cranial Form 1 | Ultrastenos willisi | Ultrastenos huberi, probably the same individual as QM F31060 |
| QM F31079 | posterior cranial fragment | White Hunter Cranial Form 2 | - | Quinkana meboldi |
| QM F42665 | posterior cranial and mandibular fragments fragments | - | Ultrastenos willisi (holotype) | Ultrastenos huberi |
| QM F61096 | articulated left and right dentaries | - | - | Ultrastenos huberi |
| QM F61097 | cranial fragment | - | - | Ultrastenos huberi |
