Gerontoformica orientalis

†Gerontoformica orientalis Temporal range: Early Cenomanian, Late Cretaceous K Pa Eo Ol Mi Pl Burmese amber, Kachin State, Myanmar
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Sphecomyrminae
Tribe:	Sphecomyrmini
Genus:	Gerontoformica
Species group:	uncertain
Species:	†G. orientalis
Binomial name
†Gerontoformica orientalis (Engel & Grimaldi, 2005)

†Gerontoformica orientalis, the type species of †Sphecomyrmodes, is identifiable as †Gerontoformica relative to †Sphecomyrma Wilson & Brown, 1967 by the absence of the anteromedian clypeal process and presence of traction setae/ chaetae along the anterior clypeal margin, as recognized in the original description (Engel & Grimaldi, 2005) and illustrated in Boudinot et al. (2020b). However, in †Gerontoformica, the species †G. orientalis is unidentifiable due to poor preservation. No details of the head are clearly observable, except for the antenna, mandibles and anterior clypeal margin, while the mesosoma appears strongly distorted, the petiole is obscured, and the metasoma is mostly disarticulated. Boudinot et al. (2020b) placed †G. orientalis in the orientalis species group along with the type species of †Gerontoformica based on the absence of the cinctus of abdominal segment IV. As a more refined placement is not possible, we newly consider this species to be a nomen dubium. (Boudinot et al., 2022)

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Distribution

This taxon was described from Burmese amber, Kachin State, Myanmar (Early Cenomanian, Late Cretaceous).

Nomenclature

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

• †orientalis. †Sphecomyrmodes orientalis Engel & Grimaldi, 2005: 5, figs. 3, 4 (w.) BURMESE AMBER (Myanmar, Cretaceous).
  • Combination in †Gerontoformica: Barden & Grimaldi, 2016: in supplemental information (not paginated).
  • Status as species: Barden & Grimaldi, 2013: 406; Barden, 2017: 3.
  • Nomen dubium: Boudinot, Richter, Katzke, et al. 2022: 8.

References

• Barden, P. & Grimaldi, D.A. 2016. Adaptive radiation in socially advanced stem-group ants from the Cretaceous. Current Biology 26: 515-521 (doi:10.1016/j.cub.2015.12.060).
• Barden, P. 2017. Fossil ants (Hymenoptera: Formicidae): ancient diversity and the rise of modern lineages. Myrmecological News 24: 1-30.
• Boudinot, B.E., Perrichot, V., Chaul, J.C.M. 2020. †Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea). ZooKeys 1005, 21–55 (doi:10.3897/zookeys.1005.57629).
• Boudinot, B.E., Richter, A., Katzke, J., Chaul, J.C.M., Keller, R.A., Economo, E.P., Beutel, R.G., Yamamoto, S. 2022. Evidence for the evolution of eusociality in stem ants and a systematic revision of †Gerontoformica (Hymenoptera: Formicidae). Zoological Journal of the Linnean Society XX:1-35 (doi:10.1093/zoolinnean/zlab097/6523228).
• Engel, M.S., Grimaldi, D.A. 2005. Primitive new ants in Cretaceous amber from Myanmar, New Jersey, and Canada (Hymenoptrea: Formicidae). American Museum Novitates 3485: 1-24 (doi:10.1206/0003-0082(2005)485[0001:PNAICA2.0.CO;2]). (page 5, figs. 3-4, worker described)
• Perfilieva, K.S. 2023. Cretaceous-Burmese-amber ants: Morphological features and community structure. Biology Bulletin Reviews 131, 38–54 (doi:10.1134/s207908642301005x).