Goniomma poschmanni

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Goniomma poschmanni
Temporal range: Oligocene Enspel Formation, Rhineland-Palatinate, Germany
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Stenammini
Genus: Goniomma
Species: G. poschmanni
Binomial name
Goniomma poschmanni
Jessen, 2020

Identification

Distribution

This taxon was described from Enspel Formation, Rhineland-Palatinate, Germany (Oligocene).

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.

Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • poschmanni. †Goniomma poschmanni Jessen, 2020: 23, fig. 9c,d (q.) GERMANY (Oligocene).

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Queen

Holotype BLw/ oG: 5.07, HL: 1.21, HW: 1.44, ED: 0.35, GeL: 0.29, ML: 0.66, MML: 0.41, SL: 1.4, AL: 2.32, AW: 1.62 (est.), HiTL: 1.13, FWL: 6.67, PL: 0.79, PH: 0.57, PPL: 0.34, PPW: 0.6, HeW: 0.23, G1L: 1.86, G1W: 1.89. Wing venation: 2M+Cu: 0.59, 1Cu: 0.66, 1M: 0.47, m-cu: 0.51, 1RS+M: 0.46, 2RS+M: 0.26. Indices: CI: 119.51, SI: 96.94, IED/HL: 29.27, IHL/AL: 52.03, Imcu: 68.89, I2RS+M/1RS+M: 58.06, I2RS+M/m-cu: 77.96, I2RS+M/2M+Cu: 45.0.

Position: Head from dorsal, alitrunk, petiole, postpetiole and first gastral segment from dorsolateral.

Colour: Body dark brown-black, legs brown.

BL about 7.37. Head clearly wider than long, with rounded occipital corners. Head tapers towards the front. Head length just reaches half length of alitrunk. Eyes are clearly located below mid length of head. Lateroventrally drawn out eyes cannot be stated. Anterior margin of clypeus smooth, slightly convex. Mandibles triangular equipped with 6–7 well-developed triangular teeth, slightly increasing in size towards apex. Marks in the sediment indicate an apical tooth which is bigger than the others and slightly curved. Antenna 12-segmented, funicular segments gradually increasing in size toward the apex. Scape distinctly protrudes beyond the occipital margin of head. Scape hardly bended at base; it looks even straight. Frontal lobes do not cover antennal condyle. Frons wide, with longitudinal striae. Alitrunk high, wide and arched. Sculpture and sutures of alitrunk not well preserved or not strongly developed. There are no indications for distinct propodeal spines. However, blunt short teeth cannot be clearly excluded because propodeum is covered by tarsi. Sclerotization of wing venation seems to be weak primarily. Cell mcu is slightly trapezoidal in shape. Veins 4M, 2Cu and 3Cu are strongly reduced respectively not well preserved. Another vein is running parallel to vein 2RS+M. It is not clear if this vein is definitely belonging to the same forewing. In all other aspects, description of the wing venation of the genus applies. Legs medium brown, they are less sclerotized or coloured. They appear almost transparent. Petiole is continuously ascending, at its highest point it shows an acute transverse ridge, top is not rounded. Descending face of petiole steep. Postpetiole wider than long, with rounded top. Helcium articulates slightly below its mid length. First gastral tergite distinctly larger than the others, with homogenous and slightly rugose surface sculpturing. Its presclerite shows integumentary foldings arranged in a semicircle. These so-called pillars are most likely part of the stridulation organ.

Paratype BLw/ oG: 5.02, HL: 1.21, HW: 1.43, ED: 0.35, GeL: 0.29, ML: 0.69, MML: 0.41, AL: 2.05, AW: 1.64, HiTL: 1.25, FWL: 7.40, PPL: 0.51, PPW: 0.59, G1L: 1.82, G1W: 2.07. Wing venation: 2M+ Cu: 0.69, 1Cu: 0.69, 1M: 0.50, m-cu: 0.50, 1RS+M: 0.46, 2RS+ M: 0.34. Indices: CI: 118.3, IED/HL: 29.27, IHL/AL: 58.96, Imcu: 65.96, I2RS+M/1RS+M: 74.19, I2RS+M/m-cu: 83.85, I2RS+ M/2M+Cu: 48, 94.

Position: All preserved body parts from dorsal.

BL about 7.65. General habitus like holotype. Mandibles triangular, apical tooth here well preserved; it is longer than the others and curved. Eyes located below mid length of head. Seen from dorsal anterior half of alitrunk wide, narrows posteriorly. Legs also brown and less sclerotized than body, appearing transparent. Tibial spines at hind leg not combed. There is no distinct sculpture identifiable, sutures on alitrunk weak as in holotype. Wing venation very similar to holotype. Vein 2Cu is preserved, vein 3Cu very thin and weak. There is no clear indication for an armed propodeum.

Type Material

Holotype: NHMM-PE2009/6281-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.

Paratype: NHMM-PE2005/5162-LS. Enspel Oilshale, Rhineland-Palatinate, Germany. Enspel Formation, Upper Oligocene, MP 28; (24.56-24.79 Ma, Mertz et al. 2007), layer S14.

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 Markus Poschmann, Koblenz, specialist in the discovery, study and publication of fossil arthropods, and supervisor at the scientific excavations in the oil shale of Lake Enspel.

References