Temporal range: 42–37 Ma Middle to Late Eocene
| Iridomyrmex oblongiceps, now Eldermyrmex oblongiceps|
| 1 fossil species|
It is curious that Wheeler (1915) did not establish a new genus for the species Eldermyrmex oblongiceps. He comments that it “does not seem to be a typical Iridomyrmex, but I know of no other genus to which it can be assigned”. His hesitation was based on the observed differences between this and other species placed in Iridomyrmex not being “very prominent”. However, the shape of the head and placement of the eyes, combined with the shape of the propodeum and petiole are unique and set this species apart from those of other genera. It is clear this species does not belong in Iridomyrmex or any other described genus, and therefore it was transferred to a new genus by Heterick and Shattuck (2011).
Head subrectangular with eyes low and lateral on head capsule (reminiscent of Tapinoma), propodeum low, with a longitudinal ridge separating the dorsal and lateral surfaces, and petiole with a low, broad cone- shaped node. This combination of characters will separate this genus from others within this subfamily.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- †ELDERMYRMEX [incertae sedis in Dolichoderinae]
- †Eldermyrmex Shattuck, in Heterick & Shattuck, 2011: 170. Type-species: †Iridomyrmex oblongiceps, by original designation.
As for the single known species, Eldermyrmex oblongiceps, see Wheeler (1915b: 93).
- Heterick, B.E. & Shattuck, S.O. 2011. Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae). Zootaxa 2845: 1–174.
- Wheeler, W. M. 1915. The ants of the Baltic Amber. Schr. Phys.-Ökon. Ges. Königsb. 55: 1-142.