Gesomyrmex breviceps, Dlussky, Gennady M., Wappler, Torsten & Wedmann, Sonja, 2009

Dlussky, Gennady M., Wappler, Torsten & Wedmann, Sonja, 2009, Fossil ants of the genus Gesomyrmex Mayr (Hymenoptera, Formicidae) from the Eocene of Europe and remarks on the evolution of arboreal ant communities, Zootaxa 2031, pp. 1-20 : 11-12

Gesomyrmex breviceps sp. nov.

( Fig. 4 B and Fig. 6 F)

Derivation of the name. Breviceps is the Latin expression for “with a short head”.

Holotype. SMF MeI 2305 (Ƥ). Paratypes (ƤƤ). SMF MeI 11054, MeI 13151.

Type locality and horizon. Grube Messel, Hesse, Germany. Messel formation, middle Eocene, ca. 47 Ma ( Mertz & Renne 2005).

Description. Gyne. BL 7–9 mm. Head subrectangular, about 1.1 times longer than wide, with feebly concave posterior margin and rounded posterolateral corners. Anterior clypeal margin projected as rounded lobe. Eyes ovate, comparatively small. Head about 3.5 times longer than maximum eye diameter and scape length. Funicular joints shorter than thick. Mandible massive, triangulate. Forewing with closed cells 1+2r, 3r, and mcu. Cell mcu rhomboidal. Vein sections RS and M with joint start from cell 1+2r (section RS+M practically absent). Coloration completely preserved only in paratype MeI 11054. Posterior part of head and most part of mesosoma yellowish brown, anterior part of head, spot near ocelli, and median parts of gastral tergites dark brown. Coloration of holotype gaster as in MeI 11054. Whole body of paratype MeI 13151 black, but probably coloration was changed during diagenesis. Wings of all specimens uniformly smoky brown, with darker veins and pterostigma.

Measurements (in mm). Holotype MeI 2305: BL 9.2, AL 2.6, HL 1.6, HW 1.5, ED 0.46, FWL 5.1; paratype MeI 11054: BL 7.2, AL 2.1, ED 0.40, FWL 5.1; paratype MeI 13151: BL 7.1, AL 1.85, FWL 4.3.

Figures

FIGURE 4. Gesomyrmex species from Messel. (A) G. p u l c h e r sp. nov., gyne, holotype MeI 10999. (B) G. breviceps sp. nov., gyne, holotype MeI 2305. (C) G. curiosus sp. nov., head of gyne, holotype MeI 11953. Scale bars = 1 mm.

FIGURE 6. Photographs of different casts and species of Gesomyrmex. (A) Gesomyrmex hoernesi Mayr – minor worker GMUG. BST. 0 4207. (B) Gesomyrmex hoernesi Mayr – worker PMHU. 13 / 221. (C) Gesomyrmex hoernesi Mayr – male MKC. F- 010. (D) Gesomyrmex hoernesi Mayr – major worker SIZK. K- 419. (E) Gesomyrmex hoernesi Mayr – gyne PMHU. 7 / 229. (F) G. b re v ic e ps sp. nov., gyne, holotype MeI 2305. (G) G. pulcher sp. nov., gyne, holotype MeI 10999. (H) G. curiosus sp. nov., head of gyne, holotype MeI 11953. (I) G. germanicus sp. nov., gyne, holotype PE- 1997 / 29. (J) G. flavescens sp. n., gyne, holotype PE- 2000 / 14. Scale bars = 1 mm.