Temporal range: Bartonian, Middle to Late Eocene Baltic amber, Baltic Sea region
Radchenko, Dlussky & Gröhn, 2019
C. groehni differs clearly from males of Carebara antiqua, first of all, by the structure of antennae. Scape in C. groehni is distinctly longer than in C. antiqua: SL/HL 0.35 vs. 0.27, ca. 3 times vs. 2 times as long as wide, and twice as long as the 2nd funicular segment vs. both being subequal in length. Furthermore, funicular segments in C. groehni are relatively shorter than in C. antiqua: the 2nd segment ca. 1.3 vs. 1.6 times as long as the 1st one; the 2nd to 4th segments ca. twice as long as wide, the 5th to 11th segments ca. 1.5 times as long as wide, but the 2nd to 10th segments are subequal in length and 2.3 times as long as wide in C. antiqua. Lastly, length of the apical segment in C. groehni is subequal to the scape length, but it is ca. 1.5 times as long as the scape in C. antiqua.
In addition, male of C. groehni is somewhat smaller: the total length is ca. 4 mm vs. ca. 5 mm in C. antiqua, and propodeum in the latter species is slightly angulate.
This taxon was described from Baltic amber (Bartonian, Middle to Late Eocene) with the date given as Late Eocene, Priabonian stage, 33.9–37.8 Ma.
Workers and queens unknown.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- †antiqua. †Pheidologeton antiquus Radchenko, Dlussky & Gröhn, 2019: 612, figs. 3, 4 (m.) BALTIC AMBER (Eocene).
- Holotype, male, Jantarny, Kaliningrad Prov., Russia, Baltic Amber (Eocene), Carsten Gröhn, GPIH No. 4991, coll. Gröhn No. 6802, collection of C. Gröhn.