Gerontoformica cretacica

†Gerontoformica cretacica Temporal range: Late Albian to Early Cenomanian, Cretaceous K Pa Eo Ol Mi Pl Charentese amber, Aquitaine Basin, France
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Sphecomyrminae
Tribe:	Sphecomyrmini
Genus:	Gerontoformica
Species group:	cretacica
Species:	†G. cretacica
Binomial name
†Gerontoformica cretacica Nel & Perrault, 2004

The holotype of †Gerontoformica cretacica is poorly preserved, as noted by Barden & Grimaldi (2016), with obvious distortions and elongation of the scapes and flagella, and little detail of the body visible. Due to this unfortunate circumstance, we newly consider †G. cretacica to be a nomen dubium. It remains in the cretacica species group of †Gerontoformica, because it is the type species of the genus. However, it will be highly desirable to clarify the identity of this species through examination and description of more Charentese ants. At present, the only distinction between †G. cretacica and the co-eval †Gerontoformica occidentalis that is not apparently affected by preservation is body size, with the former having a longer mesosoma than the latter (2.1 mm vs. 1.4 mm, respectively). Body size is, of course, highly variable among nestmates of crown ants, thus is a weak diagnostic trait when used in isolation and without the quantification of variation across conspecific individuals. (Boudinot et al., 2022)

Distribution

This taxon was described from Charentese amber, Aquitaine Basin, France (Late Albian to Early Cenomanian, Cretaceous).

Nomenclature

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

• †cretacica. †Gerontoformica cretacica Nel & Perrault, in Nel, et al. 2004: 24, figs. 1, 2 (w.) CHARENTESE AMBER (France, Cretaceous).
  • Status as species: Barden, 2017: 2.
  • 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).
• Nel, A., Perrault, G., Perrichot, V. & Néraudeau, D. 2004. The oldest ant in the Lower Cretaceous of Charente-Maritime (SW France) (Insecta: Hymenoptera: Formicidae). Geologica Acta 2: 23-29.