| Both clades, together with H. bastetanum, form a trichotomy that it is separate from H. suaveolens. |
| The dorsal siphuncles of the Clymeniida tend to be larger than the ventral siphuncles of other ammonoid clades. |
| Both clades show some overlap in their geographic distribution around the equator. |
| All these taxa are relevant to the history of the conquest of land by vertebrates because they are outside the large clades of extant tetrapods. |
| Therefore, we cannot support Durham's derivation of New World lunulate clades from an ancestor in common with protoscutellids, either. |
| Even the dentally unimaginative dinosaur clades often did better than this. |
