Table 5. Characteristics of pointed and skirted Forms A, B, C, D, and E.
| Characteristic | Form A | Form B | Form C | Form D | Form E |
| pedicle margin | slightly scalloped | slightly scalloped to undulating | scalloped with small nodes | smooth to undulating | smooth to undulating |
| pedicle base | convex | convex with anterior bulge | convex with anterior bulge | convex with anterior bulge | convex with anterior bulge |
| crown inclination (anterior to posterior) | approx. flat | <20º | >30º < 80º | >30º < 80º | >30º < 80º |
| crown curvature (anterior to posterior) | none | none to slightly convex | slightly convex | none to slightly convex | anterior convex |
| crown curvature (side to side) | slightly convex | slightly convex | convex | convex | convex |
| crown anterior longitudinal line/ridge | present | weakly to moderately scalloped | prominently scalloped | thin or absent | scalloped |
| crown anterior overhang | some | some | some to slight | none or slight | slight |
| mesial platform ridges | converge posteriorly | converge posteriorly | converge posteriorly, may fork anteriorly | converge posteriorly, may fork anteriorly | converge posteriorly, fork anteriorly |
| subcrown mesial ridge | short | present | may be present | present | present |
| stratigraphic interval | upper Eocene | upper Eocene and Oligocene | Oligocene | upper Eocene and Oligocene | lower Oligocene |
| no. specimens | 1 | 22 + 3? | 5 | 10 + 1? | 1 |