Paraphaenogaster schindleri

Identification
Jessen (2020) - Differs from Paraphaenogaster loosi by its well defined occipital corners and its long, almost parallel running frontal carinae. It is not allocated to the genus Messor because CI in Messor gyne is in most species distinctly above100. (Measurements on images from the Antweb of ten gynes from ten different extant Messor species showed an average CI of more than 106.) Also the outer line of the mandibles is not nearly as strongly bent as with the extant Messor gyne. In addition, the central backward area of the clypeus and the frontal triangle do not reach the width seen with the extant Messor gynes. Therefore, there is no strong reason to assign this sample to the genus Messor. Comparisons with fossil Messor species are hardly possible. So far, only one fossil Messor species has been described: Messor sculpturatus, Carpenter 1930 from the late Eocene deposit in Florissant, USA. This assignment, however, is equivocal and it has been generally questioned by Bolton (1982: p. 341), later Bolton (1995: p. 257) classified it as insertae sedis in Messor.

Distribution
This taxon was described from.

This species and other fossil ants were collected as part of yearly excavation campaigns between 1995 and 2013 conducted by the Directorate General for Cultural Heritage Rhineland-Palatinate, Directorate Archaeology, Department of Earth History.

Nomenclature

 * †. †Paraphaenogaster schindleri Jessen, 2020: 9, figs. 4a, b (q.) GERMANY.

Queen
Holotype BLw/ oG: 8.61, HL: 2.51, HW: 2.15, ED: 0.35, GeL: 0.68, ML: 1.47, MML: 0.76, SL: 2.02, AL: 3.74, ScuL: 1.75, ScutL: 0.68, FWL: 10.08, HiTL: 2.14, PL: 1.03, PH: 0.69, PPL: 0.56, PPH: 0.78, HeH: 0.35, Wing venation: 2M+Cu: 0.90, 1Cu: 0.93, 1M: 0.63, m-cu: 0.78, 1RS+M: 0.50, 2RS+M: 0.56. Indices: CI: 85.71, SI: 93.7, IED/HL: 14.05, IHL/AL: 67.17, Imcu: 53.97, I2RS+M/ 1RS+M: 111.76, I2RS+M/m-cu: 133.86, I2RS+M/2M+Cu: 62.30.

Position: Head dorsal, alitrunk dorsolateral, petiole lateral, postpetiole dorsolateral, gaster dorsolateral.

Colour: Black.

BL about 11.74. Head longer than wide, with almost parallel sides, and distinct occipital corners. Head does not get narrower towards the front. Posterior margin of head median with a smooth depression. Long straight frontal carinae reaches beyond the median ocellus. All dorsal parts of head completely sculptured with constant longitudinal striae. Eyes located at about midlength of head. Eyes relatively small, head more than five times longer than maximum eye diameter. Gena striated. Anterior clypeal margin smooth, median convexly shaped. Clypeus densely striated. Frontoclypeal- suture median convex, frontal triangle distinctly reaching beyond frontal lobes. Mandibles triangular. Masticatory margin with 6–8 triangular-shaped teeth. Teeth 5 and 6 seem to be slightly smaller than the others. Most apical parts of mandibles hidden in the sediment. Therefore there is no evidence for the existence of one or two distinctly enlarged and curved apical teeth. Scape just reaches posterior margin of head. Scape widely curved at base. Funiculus 11-segmented. The six proximal segments are almost as long as wide, slightly increasing in size towards apex. The six apical funicular segments continuously slightly increasing length towards apex, but they do not form a differentiated club. Alitrunk high, not arched. Scutum large, flat, overlaps pronotum anteriorly, antero-lateral corners of pronotum not visible from dorsal. Scutellum is transversely oval shaped with tapered ends. Its anterior margin is upraised (could also be caused by taphonomic processes). Propodeal declivity fairly steep. Well-developed metanotum, its posterior margin is distinctly thickened. Propodeal spines only recognizable as outlines. Propodeum could be slightly angled, provided with small pointed corners. Scutum is striated, straight in the middle, slantwise to both sides. Latter converge towards tegula. Scutellum also with coarse longitudinal ridges. Signs of tibial spurs found at all legs, simple at mid and hind legs, broader and probably brushed at foreleg. Tarsal segments of all legs with bristles. Wing venation with closed cells mcu and 1+2r. Shape of cell mcu distinctly trapezoid. Vein 1Cu almost double length of 1RS + M. In other respects, the description of the wing venation of the genus applies. Propodeum with transversal striation at posterior declivity, continuing vertical at lateral parts of propodeum. Solid, round propodeal petiolar articulation, protrudes from alitrunk. Petiole pedunculate, very stout. In profile, it appears dorsally convex. Dorsal part of petiolar node is incomplete. Postpetiole with distinct node. Ascent and descent of node medium. The node’s top seems to have another surface structure; it stands out from the rest of the postpetiole. This probably also applies for the petiole top. Helcium projects ventrally at less then mid length of petiole's anterior face. Maximum height of petiole and postpetiole is about equal. Gaster is not complete. Posterior margins of first gastral tergite and sternite are not clear because of break lines.

Type Material
Holotype: NHMM-PE2001/5065-LS, winged gyne. Enspel Oilshale, Rhineland-Palatinate, Germany. Enspel Formation, Upper Oligocene, MP 28; (24.56–24.79 Ma, Mertz et al. 2007), layer S16.

Abbreviation of specimen numbers:NHMM= Naturhistorisches Museum Mainz; PE = Palaeontology Entomology; 2009 = found in 2009; 6281 = running inventory number of the year; LS = Landessammlung (State Collection). Information on the layer is given. They refer to the standard profile in Felder et al. (1998).

Currently stored in the Directorate General for Cultural Heritage Rhineland-Palatinate, Directorate Archaeology, Department Earth History, Mainz, Germany. In the long term, they will be deposited in the “Typothek” of the State Collection of Natural History Rhineland-Palatinate/Museum of Natural History Mainz, Mainz, Germany (NHMM).

Etymology
Honouring Dr. Thomas Schindler, who developed essential models for the formation and sedimentological development of Lake Enspel and other Oligocene Lagerstätten in the Westerwald Mountains through time.