Bombus (Cullumanobombus) randeckensis Wappler and Engel in Wappler et al. (2012)

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) randeckensis Wappler and Engel in Wappler et al. (2012)

Holotype.

Sex unknown. The fossil consists of an isolated forewing. SMNS 68000/28 (old Armbruster collection No. A5119). Conserved in the Staatliches Museum für Naturkunde, Stuttgart, Germany. Type specimen has been located and revised ( Figs 2B , 3G ).

Type strata and locality.

Randeck Maar, southeast of Stuttgart, Swabian Alb; Early Miocene, i.e., 16.0-18.0 Ma (Burdigalian, Karpatian, MN 5).

Diagnosis.

Bombiform bee; infuscate area in marginal cell extends entire length of anterior half of marginal cell; forewing venation strictly similar to that of an extant bumble bee, with transector visible on both forewings. See Wappler et al. (2012) for original diagnosis.

Description.

Forewing length 14.3 mm, maximum width 5.0 mm; marginal cell length 3.9 mm; basal vein almost straight, slightly curved in its base, slightly basad cu-a; vein cu-a straight; three submarginal cells; first submarginal cell length 1.7 mm (as measured from origin of M+Rs to juncture of r-rs and Rs), width 0.8 mm (as measured from M+Rs to pterostigma); second submarginal cell width 0.7 mm (as measured from midpoint on M between 1m-cu and 1rs-m to juncture of r-rs and Rs); third submarginal cell length 1.3 mm (as measured from juncture of 1rs-m and M to juncture of M and 2rs-m), width 1.1 mm (as measured from juncture of M and 2m-cu to juncture of 2rs-m and Rs); height of second medial cell 1.1 mm (as measured from Cu1 to juncture of 1m-cu and M); 1st abscissa of Rs almost straight; 2nd abscissa of Rs with anterior half curved apically; r-rs almost straight; M+Rs straight and longer than r-rs; 3Rs almost as long as r-rs; 4Rs slight smaller than M+Rs; 1rs-m almost straight; 2rs-m with posterior half curved apically; 1m-cu curved apically in last anterior part, reaching second submarginal cell before midpoint; 2m-cu slightly curved, reaching M basad to 2rs-m. See Wappler et al. (2012) for original description.

Comments.

The fossil was discovered in the Lower Miocene (i.e., 18.0-16.0 Ma) deposits of Randeck Maar, Germany, an age and locality in general accord with the estimate that Cullumanobombus originated between 20.0-15.0 Ma in the Old World. Based on the forewing shape affinities and the general morphological assessment, B. randeckensis is likely an extinct species of Cullumanobombus , like B. trophonius .

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.