Rhytidoponera gibsoni, 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 : 1047

Rhytidoponera gibsoni new species

Figure 5.1, 5.2

Diagnosis.—May be distinguished from gynes of R. waipiata n. sp. by the more robust mesosoma, shorter appendages, and the shape of the petiole with concave anterior and posterior and flat dorsal faces of petiole.

Description.—Gyne in lateral view; total body length 11.6 mm, gaster enormously long (probably swollen due to water drift before burial). Head 1.75 mm long, 1.3 times longer than wide. Mesosoma 3.3 mm long, robust, less than twice as long as high. Dorsal and declivous sides of propodeum form rounded obtuse angle. Declivous side several times longer than dorsal side of propodeum. Legs rather short and thick. Petiole 1.1 times longer than high (1.12 mm / 1.03 mm), with concave anterior and posterior sides and flat dorsal side. Tip of gaster acute with short sting.

Etymology.—The species name honors the Gibson family on whose property the Foulden Maar lagerstätte is located.

Type.— Holotype OU44900; a laterally compressed gyne; deposited in the Department of Geology, University of Otago.

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

Remarks.—Although most key characters of Rhytidoponera are not preserved in the fossil, we assign the new species to this genus because its general habitus and particularly the distinctive petiole is very similar to some extant species of Rhytidoponera . Rhytidoponera gibsoni n. sp. differs from R. waipiata n. sp., described above, by the more robust mesosoma, shorter appendages, and by the shape of the petiole. Gynes of Gnamptogenys europaea ( Mayr, 1868) in Baltic amber resemble R. gibsoni in the position of the helcium and by the robust mesosoma. However, their propodeum is distinctly angulated and the petiolar node is rounded in side view.