Gerontoformica tendir

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Gerontoformica tendir
Temporal range: Early Cenomanian, Late Cretaceous 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. tendir
Binomial name
Gerontoformica tendir
(Barden & Grimaldi, 2014)

Barden & Grimaldi, 2014-12Sphecomyrmodes-tendir2.jpg

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