†Proiridomyrmex rotundatus LaPolla & Greenwalt, 2015: 166, figs 4, 5 (q.) U.S.A. (Montana, Eocene, Lutetian).

Primary type information: Primary type material: holotype queen. Primary type locality: U.S.A.: Montana: Middle Fork of the Flathead River between Paola and Coal Creeks; Kishenehn Formation. Primary type depository: USNM. Primary type specimen: USNM# 609586. Secondary type information: Secondary type material: 3 paratype queens. Secondary type locality: same as for holotype. Secondary type depository: USNM. Secondary type specimens: USNM# 609587, USNM# 609588, USNM# 609589.