Gerontoformica tendir
†Gerontoformica tendir Temporal range: Early Cenomanian, Late Cretaceous Burmese amber, Kachin State, Myanmar | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Sphecomyrminae |
Tribe: | Sphecomyrmini |
Genus: | Gerontoformica |
Species group: | uncertain |
Species: | †G. tendir |
Binomial name | |
†Gerontoformica tendir (Barden & Grimaldi, 2014) |
Identification
Boudinot et al. (2022) - †Gerontoformica rugosa and †Gerontoformica tendir are newly considered as nomina dubia due to their poor preservation, being strongly desiccated and thus distorted. Both species appear to have some degree of abdominal segment III petiolation, as observed in the three confirmed members of the pilosa group, but it cannot be determined whether this is natural or exaggerated due to preservation. It is possible, but not yet determinable, that †G. rugosa is conspecific with †G. gracilis. That †G. rugosa or †G. tendir do have sculptured integument remains possible but requires substantiation via additional material of these species. We note that little surface texture variation has been explicitly documented among stem ants thus far.
†Gerontoformica tendir was defined by Barden & Grimaldi (2014) as having a medial clypeal lobe. This anteromedian lobe not only bears traction setae/chaetae, as previously observed, but is also lateromedially broader and proximodistally shorter than that of †Sphecomyrma. Given the poor preservation, it is possible that the apparent lobate form may be due to distortion of the amber matrix, as the lobe consists of the entire medial portion of the clypeus, which is distinct from the lateral clypeal lobes. Based on direct examination of the holotype, it appears that there is a transverse mesonotal carina in †G. tendir, but this also requires re-evaluation. Without additional specimens having an exaggerated and broadly, medially lobate clypeus, we remain uncertain about the identity of the species. A state of potential value for confirming the identity of †G. tendir from additional material is the absence of teeth on the pretarsal claws, as illustrated by Barden & Grimaldi (2014).
Distribution
This taxon was described from Burmese amber, Kachin State, Myanmar (Early Cenomanian, Late Cretaceous).
Castes
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- †tendir. †Sphecomyrmodes tendir Barden & Grimaldi, 2014: 17, fig. 9A-C (w.) BURMESE AMBER (Myanmar, Cretaceous).
- Combination in †Gerontoformica: Barden & Grimaldi, 2016: in supplemental information (not paginated).
- Status as species: Barden, 2017: 3.
- Nomen dubium: Boudinot, Richter, Katzke, et al. 2022: 9.
Description
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).