Temporal range: Lutetian, Middle Eocene Arkansas amber, Malvern, Arkansas, United States
The condition of the only known specimen of this species is so poor that discussions of its morphology are limited to the most general and vague characterisation. Wilson (1985a) notes that the species possesses fewer mandibular teeth than New World species then placed in Iridomyrmex (now placed in Linepethima). He compares the mandibles with those of extant Australian species, finding them similar to Iridomyrmex calvus and Iridomyrmex rufoniger, as well as what is now Philidris cordata. Essentially no other details are provided. With so little information available it is impossible to support a specific generic placement of this taxon, and Heterick and Shattuck (2011) retained it in Iridomyrmex as incertae sedis, acknowledging that this placement is unsupported and likely to be incorrect based on biogeographic considerations and the great age difference between this species and the origins of modern members of Iridomyrmex.
This taxon was described from Arkansas amber, Malvern, Arkansas, United States (Lutetian, Middle Eocene).
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- †mapesi. †Iridomyrmex mapesi Wilson, 1985d: 211, figs. 4, 5 (w.) U.S.A. Provisionally retained in Iridomyrmex: Shattuck, 1992a: 16. Unidentifiable taxon, incertae sedis in Iridomyrmex: Heterick & Shattuck, 2011: 168.
- Shattuck, S. O. 1992a. Review of the dolichoderine ant genus Iridomyrmex Mayr with descriptions of three new genera (Hymenoptera: Formicidae). J. Aust. Entomol. Soc. 31: 13-18 (page 16, Provisionally retained in Iridomyrmex)
- Wilson, E. O. 1985f. Ants from the Cretaceous and Eocene amber of North America. Psyche (Camb.) 92: 205-216 (page 211, figs. 4, 5 worker described)