Genus and Species

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 : 1045

Genus and Species indet.

Figure 3.1, 3.2

Description.—Part and counterpart of gyne in dorsal view, head not preserved; body length (without head) 8.7 mm, estimated total body length about 10 mm, mesosoma length 3.3 mm; mesosoma width 1.4 mm, petiole length 1.37 mm, petiole width 1.05 mm.

Mesosoma elongate, 2.3 times longer than wide, with nearly parallel sides. Legs comparatively short and thick. Middle tibia with two spurs; first and second segments of middle tarsus both with a pair of long setae. Petiole a little longer than wide, with short anterior peduncle, without free posterior surface, broadly attached to first gastral segment, separated from gaster only by constriction. Second gastral segment a little wider and about as long as first segment. Tip of gaster acute, indicating the probable presence of a sting. Wings fragmentary preserved; wing venation indistinct.

Material.—Specimen OU44898; gyne, dorsoventrally compressed, head not preserved; deposited in the Department of Geology, University of Otago.

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

Remarks.—The assignment of the fossil as an amblyoponine ant is based on the construction of the petiole and the general habitus; two features that have been regarded traditionally as reliable for the subfamily Amblyoponinae ( Brown, 1960) . Genera of Malagasy Amblyoponinae were revised by Yoshimura and Fisher (2012), who reassigned species of Amblyopone sensu lato into Xymmer Santschi, 1914 , Amblyopone Erichson, 1842 sensu stricto and Stigmatomma Roger, 1859 , based on male morphological characters, which are not applicable to the gyne from Foulden Maar, as are morphological characters of workers (e.g. Brown, 1960; Taylor, 1987). Two extant members of Amblyoponinae are present in the New Zealand fauna: the endemic S. saundersi ( Forel, 1892) and the introduced A. australis Erichson, 1842 ; only gynes of the latter species approach the size of the fossil. In the absence of morphological characters such as the structure of mandibles and wing venation, we assign the fossil to tribe Amblyoponini without placement into an extinct or extant genus.

Published fossil Amblyoponinae include a winged male without generic placement from Foulden Maar ( Kaulfuss et al., 2014a), Casaleia inversa ( Dlussky, 1981) ( Kyrgyzstan, Middle Miocene), C. longiventris ( Heer, 1849) (early Miocene, Croatia), Myopopone sinensis Zhang, 1989 (Shanwang, China, early Miocene) and, from the Eocene Messel pit in Germany Stigmatomma groehni ( Dlussky, 2009) , S. electrinum ( Dlussky, 2009) , and C. eocenica ( Dlussky and Wedmann, 2012) . Two of these species, C. eocenica and C. longiventris , were based on gynes, which can by readily distinguished from the gyne described here by a smaller body size and a much shorter and wider gaster ( C. eocenica ) and a wider petiole and first gastral segment, differing proportions of the gastral segments (in dorsal aspect) and a less pointed tip of the gaster ( C. longiventris ).