Myrmecorhynchus novaeseelandiae, Uwe Kaulfuss & Gennady M. Dlussky, 2015

Uwe Kaulfuss & Gennady M. Dlussky, 2015, Early Miocene Formicidae (Amblyoponinae, Ectatomminae,? Dolichoderinae, Formicinae, and Ponerinae) from the Foulden Maar Fossil Lagerstätte, New Zealand, and their biogeographic relevance, Journal of Paleontology 89 (6), pp. 1043-1055 : 1048-1049

Myrmecorhynchus novaeseelandiae new species

Figure 7.1–7.3

Diagnosis.—Male: waist with one segment (petiole). Antennae 13-segmented, geniculate, scape long, protrudes beyond the occipital margin of the head, all funicular segments longer than thick. Propodeum gradually rounded in side view. Forewing with closed cells 1 + 2r, 3r and mcu; closed cell rm absent. Vein sections 5RS and 4M with joint start (rs-m lost); cross-vein cu-a displaced to the base of wing.

Description.—Part and counterpart of laterally compressed male. Body length about 6 mm, mesosoma length 2.2 mm, head length about 0.75 mm, head width about 0.85 mm. Head rounded, a little wider than long, mandibles presumably long, more than one-third of head length (outline of mandibles not visible). Antennae 13-segmented, geniculate, scape long, protrudes beyond the occipital margin of the head, all funicular segments longer than thick. Scutum overhangs pronotum. Propodeum gradually rounded in side view. Petiole indistinct. Genital parameres nearly as long as wide, with rounded tip.

Forewing 4.8 mm long, with closed cells 1 + 2r, 3r and mcu; closed rm absent. Pterostigma well developed. Vein sections 5RS and 4M with jointed start (rs-m lost). Cell 3r 4 times longer than wide. Cell 1 + 2r nearly three times longer than wide. Cell mcu trapezoid (RS + M appreciably shorter than 1Cu). Vein 1RS shorter than 1M. Cross-vein cu-a displaced to the base of wing; vein section 2M + Cu longer than 1Cu and three times as long as cu-a.

Etymology.— Novaeseelandiae refers to New Zealand, where this species was once native.

Type.— Holotype OU44569 (part and counterpart); a laterally compressed winged male; deposited in the Department of Geology, University of Otago.

Occurrence.—Foulden Maar diatomite, Waipiata Volcanic Field, Otago, New Zealand; early Miocene.

Remarks.—The wing venation of the new species is usual among genera of Formicinae . Some members of Dolichoderinae and Myrmicinae have a similar venation, but male representatives of these subfamilies possess antennae with a short scape. The six extant formicine species known from New Zealand are the endemics Prolasius advenus ( F. Smith, 1862) and Camponotus (Colobopsis) newsealanicus Donisthorpe, 1940 and the introduced Anoplolepis gracilipes ( F. Smith, 1857) and three species of Paratrechina Motschoulsky, 1863 ( Brown, 1958a; Taylor, 1987; Don, 2007). All species of these genera have forewings without a closed cell mcu, so the new species cannot belong to these taxa.

Native species of the following 18 formicine genera are known in the extant Australasian fauna: Calomyrmex Emery, 1895a ; Camponotus Mayr, 1861 ; Echinopla F. Smith, 1857 ; Opisthopsis Dalla Torre, 1893 ; Polyrhachis F. Smith, 1857 (tribe Camponotini Forel); Acropyga Roger, 1862 ; Prolasius Forel, 1892 ; Stigmacros Forel, 1905 ; Teratomyrmex McAreavey, 1957 ( Lasiini Ashmead); Melophorus Lubbock, 1883 ( Melophorini Forel); Myrmecorhynchus Andrè, 1896 ; Notoncus Emery, 1895b ; Pseudonotoncus Clark, 1934b ( Myrmecorhynchini Wheeler); Notostigma Emery, 1920 ( Notostigmatini Bolton); Oecophylla F. Smith, 1860 ( Oecophyllini Emery); Paratrechina Motschoulsky, 1863 ; Plagiolepis Mayr, 1861 ; and Pseudolasius Emery, 1887 ( Plagiolepidini Forel) ( Taylor, 1987). Winged Teratomyrmex and Pseudonotoncus are not known. Amongst the remaining genera, the cell mcu is present only in Opisthopsis , Myrmecorhynchus and Notoncus , while wings of representatives of other genera are lacking this cell ( Emery, 1925). In Opisthopsis , the cell mcu is either triangulate ( O. haddoni Emery, 1893 , O. major Forel, 1902 ) or absent (male of O. respiciens moestus Wheeler, 1918 ). In Notoncus , the cell mcu is present in gynes but absent in males. Only in Myrmecorhynchus both gynes and males have a trapezoid cell mcu ( Clark, 1934a). Similar wing venations occur in Formicini Latreille ( Formica Linnaeus, 1758 ; Cataglyphis Förster, 1850 , etc.) and some Lasiini ( Lasius Fabricius, 1804 ; Acanthomyops Mayr, 1862 ; Myrmecocystus Wesmael, 1838 ). However, all representatives of these genera inhabit the Northern Hemisphere, and there are no reasons to suppose that they were present in the Australasian region in the early Miocene. Similar wing venations are also present in Gesomyrmex Mayr, 1868 and Drymomyrmex Wheeler, 1915 . The native range of extant Gesomyrmex extends from the highlands of southern Borneo north into western India. In the Eocene, they also lived on the territory of modern Europe ( Dlussky et al., 2009). Drymomyrmex is known exclusively from late Eocene Baltic amber ( Wheeler, 1915). The new species can be excluded from these genera because of the following differences: males of Gesomyrmex have much larger eyes and very short 8–11 segmented antennae. Only the gynes of Drymomyrmex are known and they possess 11-segmented antennae. Usually, in all known ants whose females have less than 12 antenna segments, males have less than 13 segments. We therefore consider the new species as a member of the genus Myrmecorhynchus . An additional argument in favor of Myrmecorhynchus is the similar length of mandibles in the new species, whereas males of the majority of other ants exhibit shorter mandibles.