Gesomyrmex hoernesi

†Gesomyrmex hoernesi Temporal range: Bartonian, Middle to Late Eocene K Pa Eo Ol Mi Pl Baltic amber, Baltic Sea region
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Gesomyrmecini
Genus:	Gesomyrmex
Species:	†G. hoernesi
Binomial name
†Gesomyrmex hoernesi Mayr, 1868
Synonyms
Dimorphomyrmex mayri Wheeler, W.M., 1915 Dimorphomyrmex theryi Emery, 1905 Gesomyrmex annectens Wheeler, W.M., 1915

Identification

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  Cephalic morphometrics of gynes for relevant fossil Gesomyrmex species. (a) Head length (HL). (b) Normalized head shape (head length/head width, HRN, squares) and normalized relative eye diameter (eye diameter/head length, HERN, diamonds). Abbreviations: flav., flavescens; germ., germanicus; hoern., hoernesi. (Aria et al., 2023, Fig. 4)

Distribution

This taxon was described from Baltic amber (Bartonian, Middle to Late Eocene) and is also known from Bitterfeld amber (Bartonian, Middle to Late Eocene), Danish-Scandinavian amber (Bartonian, Middle to Late Eocene) and Rovno amber (Priabonian, Late Eocene) (Perkovsky, 2016).

Nomenclature

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

• †hoernesi. †Gesomyrmex hoernesi Mayr, 1868c: 52, pl. 2, figs. 38-41 (w.m.) BALTIC AMBER (Eocene). Dlussky, Wappler & Wedmann, 2009: 8 (q.). Senior synonym of †annectens, †mayri, †theryi: Wheeler, W.M. 1929a: 11.
• †theryi. †Dimorphomyrmex theryi Emery, 1905b: 188, fig. 1 (w.) BALTIC AMBER (Eocene). Junior synonym of †hoernesi: Wheeler, W.M. 1929a: 11.
• †annectens. †Gesomyrmex annectens Wheeler, W.M. 1915h: 107, fig. 52 (w.) BALTIC AMBER (Eocene). Junior synonym of †hoernesi: Wheeler, W.M. 1929a: 11.
• †mayri. †Dimorphomyrmex mayri Wheeler, W.M. 1915h: 106, fig. 51 (w.) BALTIC AMBER (Eocene). Junior synonym of †hoernesi: Wheeler, W.M. 1929a: 11.

References

• Aria, C., Jouault, C., Perrichot, V., Nel, A. 2023. The megathermal ant genus Gesomyrmex (Formicidae: Formicinae), palaeoindicator of wide latitudinal biome homogeneity during the PETM. Geological Magazine, 1–11 (doi:10.1017/s0016756822001248).
• Boudinot, B.E., Borowiec, M.L., Prebus, M.M. 2022. Phylogeny, evolution, and classification of the ant genus Lasius, the tribe Lasiini and the subfamily Formicinae (Hymenoptera: Formicidae). Systematic Entomology 47, 113-151 (doi:10.1111/syen.12522).
• Mayr, G. 1868c. Die Ameisen des baltischen Bernsteins. Beitr. Naturkd. Preuss. 1: 1-102 (page 52, pl. 2, figs. 38-41 worker, male described)
• Perkovsky, E.E. 2016. Tropical and Holoarctic ants in late Eocene ambers. Vestnik zoologii 50(2): 111–122 (doi:10.1515/vzoo-2016-0014).
• Radchenko, A.G., Perkovsky, E.E., Vasilenko, D.V. 2021. Formica species (Hymenoptera, Formicidae, Formicinae) in late Eocene Rovno amber. Journal of Hymenoptera Research 82, 237–251 (doi:10.3897/jhr.82.64599).
• Sosiak, C. E., Borowiec, M. L., Barden, P. 2022. An Eocene army ant. Biology Letters 18: 20220398 (doi:10.1098/rsbl.2022.0398).
• theryi:)
• Wheeler, W. M. 1929a. The identity of the ant genera Gesomyrmex Mayr and Dimorphomyrmex Ernest André. Psyche (Camb.) 36: 1-12 (page 11, Senior synonym of