Bombus vetustus, Rasnitsyn & Michener, 1991, species inquirenda

Dehon, Manuel, Engel, Michael S., Gerard, Maxence, Aytekin, A. Murat, Ghisbain, Guillaume, Williams, Paul H., Rasmont, Pierre & Michez, Denis, 2019, Morphometric analysis of fossil bumble bees (Hymenoptera, Apidae, Bombini) reveals their taxonomic affinities, ZooKeys 891, pp. 71-118 : 71

" Bombus " vetustus Rasnitsyn & Michener, 1991, species inquirenda

Holotype.

Male. #2054/229, part and counterpart impressions of an entire male, deposited in the Palaeontological Institute, Russian Academy of Science, Moscow. Type specimen was located and revised ( Figs 2C , 3H ).

Type strata and locality.

Upper Miocene (i.e., 11.2-7.1 Ma), Botchi Formation, located on the left bank of the Botchi River, Russia.

Description.

Male: Forewing length 10.4 mm as preserved; basal vein long and slightly basad cu-a; cu-a straight; marginal cell length approximately 3.3 mm, width approximately 0.7 mm as preserved; 1st abscissa of Rs straight; 2nd abscissa of Rs relatively straight; r-rs almost straight; Rs+M slightly curved and slightly longer than r-rs; 3Rs smaller than r-rs; 4Rs slightly longer than Rs+M; three submarginal cells; first submarginal cell length 1.3 mm (as measured from origin of Rs+M to juncture of r-rs and Rs), width 0.6 mm (as measured from Rs+M to pterostigma); second submarginal cell length 1.1 mm (as measured from juncture of Rs+M and M to juncture of Rs and 1rs-m), width 0.6 mm (as measured from midpoint on M between 1m-cu and 1rs-m to juncture of r-rs and Rs); third submarginal cell length 1.2 mm (as measured from juncture of 1rs-m and M to juncture of M and 2rs-m), width 0.9 mm (as measured from juncture of M and 2m-cu to juncture of 2rs-m and Rs); 2rs-m with posterior half curved apically, 1m-cu reaching M near midpoint; 2m-cu curved and reaching M basad to 2rs-m; prosoma length 3.9 mm; profemur length 1.9 mm; protibial length 1.8 mm; basitarsus length 1.6 mm; setae of pro- and mesosoma dark; total body length 19.2 mm as preserved. See Rasnitsyn and Michener (1991) for original description.

Comments.

Given that this is a male specimen, further work is needed with comparisons of its forewing shape with a diverse dataset based on males. In addition, the venation is incompletely preserved and so hopefully further and more complete material will be discovered.

Figures

Figure 2. Representative fossil bumble bees A Bombus (Cullumanobombus) trophonius (photograph by Jakup Prokop) B B. (Cullumanobombus) randeckensis (photograph by Torsten Wappler) C B. vetustus (photograph by Alexandr P. Rasnitsyn) D B. (Cullumanobombus) pristinus (photograph by Irene Zorn and Monika Brueggeman-Ledolter) E B. (Melanobombus) cerdanyensis (photograph by Thibaut De Meulemeester).

Figure 3. Forewing drawings of the fossil bumble bees studied herein. Some forewings were mirrored to enable comparison across all specimens A Oligobombus cuspidatus (mirrored) B Holotype of Calyptapis florissantensis (mirrored) C C. florissantensis D Bombus (Paraelectrobombus) patriciae (mirrored) E B. (Mendacibombus) beskonakensis F B. (Cullumanobombus) trophonius (mirrored) G B. (Cullumanobombus) randeckensis (mirrored) H B. vetustus I B. (Cullumanobombus) pristinus (mirrored) J B. (Melanobombus) cerdanyensis.