Rhytidoponera waipiata, 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 : 1046-1047

Rhytidoponera waipiata new species

Figure 4.1–4.3

Diagnosis.—Gyne: Body length about 6 mm; petiole 1.8 times longer than high, with short peduncle and low node, somewhat angulated in side view; forewing with closed cells 1 + 2r, 3r, rm and mcu; cross-vein cu-a meets M + Cu near cell mcu, proximal to section 1M, at a distance less than cu-a length. May be distinguished from R. kirghizorum Dlussky, 1981 ( Kyrgyzstan, Miocene) by body size (3.8 mm in R. kirghizorum ) and form of the petiole (rounded in side view in R. kirghizorum ).

Description.—Part and counterpart of winged gyne, partly preserved in lateral view; length of preserved compression 4.7 mm, estimated total body length about 6 mm. Outlines of head and mouth parts obscure, head apparently longer then wide; mandibles rather short and apparently triangulate. Scape 1.2 mm long, longer than head (in living ant extending more than one-third of its length beyond the posterior corners of the head), funicular joints longer than thick. Mesosoma elongate, 2.5 times longer than high (2.8 mm / 1.1 mm); dorsum of propodeum gradually rounded in lateral view. Legs rather long, tibial spur visible only on fore tibia. Pretarsal claws (visible on a fragment of middle leg) with median tooth. Petiole 1.9 times longer than high (0.77 mm / 0.41 mm), with short peduncle and low node, somewhat angulate in side view. Helcium projects from about mid-height of anterior face of first gastral segment; dorsum of first gastral tergite gradually rounded above the helcium. First gastral sternite anteriorly with sharp angle. Head, mesosoma and petiole with coarse sculpture, visible as rows of grooves along sutures (partially filled by sediment).

Wing with veins and knots partly preserved. Cells 1 + 2r, rm and mcu closed, cells 1r and cua probably closed. Cell mcu pentagonal, but vein section 2M very short. Cross-veins 2r-rs and r-m meeting RS almost at one point; cross-vein cu-a close to cell mcu: vein section 2M + Cu shorter than cu-a.

Etymology.—The species name refers to the Waipiata Volcanic Field, New Zealand, where the fossil was found.

Type.— Holotype OU44899 (part and counterpart); 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.—The distal position of the cross-vein cu-a is a character found in Myrmeciinae , Dorylinae and poneromorph subfamilies. The new species cannot belong to Myrmeciinae since they have longer mandibles (0.7–1.2 times as long as head). Dorylinae have wingless gynes (except most ants in the former subfamily Cerapachyinae ) and differ in general wing venation. The poneromorph subfamily-group includes Amblyoponinae , Ectatomminae , Heteroponerinae , Paraponerinae , Ponerinae and Proceratiinae . Paraponerinae include the sole genus Paraponera F. Smith, 1858 , with one extant and one extinct species from the Neotropical Region. The new species differs from Paraponera in many habitual characters. In Amblyoponinae , the helcium projects from a very high position on the anterior face of abdominal segment III and in Ponerinae the helcium projects from a very low position on the anterior face of abdominal segment III, the latter with a high vertical anterior face above the helcium. Proceratiinae have an extremely large abdominal segment III. These characters are not found in the new species, which may therefore belong to Ectatomminae or Heteroponerinae . These subfamilies include the genera Ectatomma F. Smith, 1858 ; Gnamptogenys Roger, 1863 ; Rhytidoponera Mayr, 1862 ; Typhlomyrmex Mayr, 1862 ; Acanthoponera Mayr, 1862 ; Aulacopone Arnoldi, 1930 ; and Heteroponera Mayr, 1887 . The new species can be excluded from Ectatomma , Typhlomyrmex , and Acanthoponera because these genera are only known from the Neotropical Region. The known species of Gnamptogenys , Aulacopone and Heteroponera differ from the new species in having rather short legs and scapes, a more compact mesosoma, and often an angulated propodeum. Only some Australian Rhytidoponera have relatively long legs and a long scape, elongated mesosoma, and a long propodeum with a gradually rounded dorsum. We therefore assign the new species to the genus Rhytidoponera , subfamily Ectatomminae .

The only described extinct species of Rhytidoponera is R. kirghizorum Dlussky, 1981 reported from the Miocene of Chon-Tuz, Kotchkorka District, Kyrgyzstan. It differs from R. waipiata n. sp. by its smaller size (3.8 mm) and by the form of the petiole (rounded in side view).