Bombus (Cullumanobombus) pristinus Unger, 1867

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 (Cullumanobombus) pristinus Unger, 1867

Holotype.

Inventory number GBA 1867/004/0004. Sex unknown. The holotype is currently deposited in the Geologische Bundesanstalt (Vienna, Austria). Type specimen has been located and revised ( Figs 2D , 3I ).

Type strata and locality.

Upper Miocene (i.e., 11.2-7.1 Ma), Kumi deposit, Euboea Island (Euboea, Greece).

Diagnosis.

Basal vein long and almost straight, basad to apically curved cu-a; pterostigma slightly longer than prestigma: second abscissa of Rs with anterior half curved apically; three submarginal cells of approximately same size; 1rs-m almost straight; 2rs-m posterior half curved apically; 1m-cu with anterior half curved apically, reaching second submarginal cell slightly before midpoint; 2m-cu very slightly curved, reaching M basad to 2rs-m.

Description.

Forewing length approximately 16.0 mm, maximum width 4.3 mm as preserved; forewing membrane hyaline, venation black becoming grey when reaching apex of forewing; marginal cell length 4.9 mm, width 1.2 mm; basal vein long and almost straight, basad cu-a; vein cu-a curved apically; pterostigma slightly longer than prestigma; three submarginal cells; first submarginal cell length 2.1 mm (as measured from origin of Rs+M to juncture of r-rs and Rs), width 0.9 mm (as measured from Rs+M to pterostigma); second submarginal cell length 2.2 mm (as measured from juncture of Rs+M and M to juncture of Rs and 1rs-m), width 0.9 mm (as measured from midpoint on M between 1m-cu and 1rs-m to juncture of r-rs and Rs); third submarginal cell length 1.6 mm (as measured from juncture of 1rs-m and M to juncture of M and 2rs-m), width 1.3 mm (as measured from juncture of M and 2m-cu to juncture of 2rs-m and Rs); second abscissa of Rs with anterior half curved apically; 1rs-m almost straight; 2rs-m posterior half curved apically; 1m-cu with anterior half curved apically, reaching second submarginal cell slightly before midpoint; 2m-cu very slightly curved, reaching M basad to 2rs-m. It seems that a transector vein is visible on the first submarginal cell, but it might be an artefact created by the taphonomic alteration of the specimen. See Unger (1867) for original description.

Comments.

The type of B. pristinus consists of just one right forewing. The specimen was described and illustrated by Unger (1867). The illustration, displaying a left forewing, is reversed left to right. Unger attributed the species to Regenhofer but, according to Rasnitsyn and Michener (1991), the latter appears not to have written the comments or prepared the illustration of Unger’s work, thus making them conclude that the name must be attributed to Unger. Based on morphological and geometric morphometric analyses, it is likely that this fossil is an extinct species of Cullumanobombus .

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.