Naming

In 1934 entomologist John S. Clark published a formal description of Nothomyrmecia macrops as a new species and within a completely new genus and tribe (Nothomyrmecii) of the Ponerinae^. He did so because the two specimens (which then became the syntypes) bore no resemblance to any ant species he knew of, but they did share similar morphological characteristics with the extinct genus Prionomyrmex. Clark notes that the head and mandibles of Nothomyrmecia and Prionomyrmex are somewhat similar, but the two can be distinguished by the appearance of the node (a segment between the mesosoma and gaster).^[4] In 1951, Clark proposed the new ant subfamily Nothomyrmeciinae for his Nothomyrmecia, based on morphological differences with other ponerine ants. This proposal was rejected by American entomologist William Brown Jr., who placed it in the subfamily Myrmeciinae with Myrmecia and Prionomyrmex, under the tribe Nothomyrmeciini. its distant relationship with extant ants was confirmed after its rediscovery, and its placement within the Formicidae was accepted by most scientists until the late 1980s. The single waist node led scientists to believe that Nothomyrmecia should be separate from Myrmecia and retained Clark’s original proposal. This proposal would place the ant into its own subfamily, despite many familiar morphological characteristics between the two genera. This separation from Myrmecia was retained until 2000.^{[21][22][23][24]}

Label of one of the Nothomyrmecia specimens collected by Taylor

In 2000, entomologist Cesare Baroni Urbani described a new Baltic fossil Prionomyrmex species (P. janzeni). After examining specimens of Nothomyrmecia, Baroni Urbani stated that his new species and N. macrops were so morphologically similar that they belonged to the same genus. He proposed that the name Prionomyrmex should replace the name Nothomyrmecia (which would then be just a synonym), and also that the subfamily Nothomyrmeciinae should be called Prionomyrmeciinae.^[24]

In 2003, Russian palaeoentomologists G. M. Dlussky and E. B. Perfilieva separated Nothomyrmecia from Prionomyrmex on the basis of the fusion of an abdominal segment.^[25] In the same year, American entomologists P. S. Ward and S. G. Brady reached the same conclusion as Dlussky and Perfilieva and provided strong support for the monophyly of Prionomyrmex. Ward and Brady also transferred both taxa as distinct genera in the older subfamily Myrmeciinae under the tribe Prionomyrmecini.^[25][26] In 2005 and 2008, Baroni Urbani suggested further evidence in favour of his former interpretation as opposed to Ward and Brady’s.^[27][28] This view is not supported in subsequent relevant papers, which continue to use the classification of Ward and Brady, rejecting that of Baroni Urbani.^{[29][30][31][32]}

The ant is commonly known as the dinosaur ant, dawn ant, or living fossil ant because of its plesiomorphic body structure.^[10][30][33] The generic name Nothomyrmecia means “false bulldog ant”.^[10] Its specific epithet, macrops (“big eyes”), is derived from the Greek words makros, meaning “long”, or “large”, and ops, meaning “eyes”.^[10][34][35]