Carebara groehni

Identification
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.

Distribution
This taxon was described from with the date given as Late Eocene, Priabonian stage, 33.9–37.8 Ma.

Castes
Workers and queens unknown.

Nomenclature

 * † antiqua. †Pheidologeton antiquus Radchenko, Dlussky & Gröhn, 2019: 612, figs. 3, 4 (m.) BALTIC AMBER (Eocene).