Gerontoformica gracilis

†Gerontoformica gracilis 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:	gracilis
Species:	†G. gracilis
Binomial name
†Gerontoformica gracilis (Barden & Grimaldi, 2014)

Distribution

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

Castes

  X-ray micro-CT scan 3D model of Gerontoformica gracilis (worker) prepared by the Economo lab at OIST.

This is a 3D model of a fossilized ant first presented in the scientific article ‘Evidence for the evolution of eusociality in stem ants and a systematic revision of †Gerontoformica (Hymenoptera: Formicidae)’ published in the Zoological Journal of the Linnean Society by Brendon E. Boudinot and others. The ant was identified and described as Gerontoformica gracilis from a piece of Cretaceous amber about 99 million years old (collection ID: AMNH Bu-SY23; specimen ID: CASENT0741232). To create the 3D model, the amber was micro-CT scanned. Adrian Richter created the model using segmentation techniques, Shuhei Yamamoto took the photo, and Julian Katzke scanned it and uploaded it to Sketchfab. See on Sketchfab. See list of 3D images.

Nomenclature

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

• †gracilis. †Sphecomyrmodes gracilis Barden & Grimaldi, 2014: 4, figs. 2A-C, 10B, 11C, 11D (w.) BURMESE AMBER (Myanmar, Cretaceous).
  • Combination in †Gerontoformica: Barden & Grimaldi, 2016: in supplemental information (not paginated).
  • Status as species: Barden, 2017: 3; Boudinot, Richter, Katzke, et al. 2022: 18, 27 (redescription, in key).

References

• Barden, P. & Grimaldi, D. 2014. A diverse ant fauna from the mid-Cretaceous of Myanmar (Hymenoptera: Formicidae). PLoS ONE 9(4): e93627.
• 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).
• Perfilieva, K.S. 2023. Cretaceous-Burmese-amber ants: Morphological features and community structure. Biology Bulletin Reviews 131, 38–54 (doi:10.1134/s207908642301005x).
• Richter, A., Boudinot, B., Yamamoto, S., Katzke, J., Beutel, R. G. 2022. The first reconstruction of the head anatomy of a Cretaceous insect, †Gerontoformica gracilis (Hymenoptera: Formicidae), and the early evolution of ants. Insect Systematics and Diversity 6(5): 1-80 (doi:10.1093/isd/ixac013).