Bryopompilidae, Rodriguez et al.

Rodriguez, Juanita, Waichert, Cecilia, Von Dohlen, Carol D., Jr., George Poinar & Pitts, James P., 2016, Eocene and not Cretaceous origin of spider wasps: Fossil evidence from amber, Acta Palaeontologica Polonica 61 (1), pp. 89-96 : 93-95

Family Bryopompilidae nov.

Type genus: Bryopompilus Engel and Grimaldi, 2006 with type species Bryopompilus interfector Engel and Grimaldi, 2006 based on the holotype ( AMNH Bu-051), complete female inclusion from Tanai Village (on Ledo Road 105 km NW Myitkyna), Kachin, Burma, early Cenomanian .

Diagnosis.—Presence of an angularly protruding, rounded lobe on the posterior margin of the pronotum; the lobe is deeply incised, overlapping the anterior and posterior margins of the wing base. The mesepisternal groove is interrupted, not reaching the mesopleural margin. The fore wing has the Rs vein straight and attached to the distal wing margin; the costal vein reaches the wing distal margin, and the Rs vein of cell 1Rs is attached to the base of 1 R 1.

Remarks.—The single known specimen from Burmese amber, Bryopompilus interfector Engel and Grimaldi, 2006 , is unusual as it is so much older than all other described Pompilidae fossils. Upon re-examining this specimen (not figured in this paper), we discovered that it does not have the diagnostic characters of Pompilidae (see Engel and Grimaldi 2006: figs. 1–5). The specimen exhibits a conspicuous, angularly protruding, rounded lobe on the posterior margin of the pronotum, which is absent in Pompilidae . Moreover, the jugal lobe is absent from the wing of this specimen, while present in Pompilidae , and the wing venation greatly differs from that of Pompilidae . In Bryopompilus interfector the Rs vein is not rounded and is attached to the distal wing margin, the costal vein reaches the wing distal margin, and the Rs vein of the cell 1Rs is not attached to the base of the cell 2 R 1 but to the base of 1 R 1. The presence of a mesepisternal groove in Bryopompilus interfector could be confused with the same structure that defines Pompilidae . Nevertheless, the mesepisternal groove covers the whole mesopleuron in Pompilidae , while in B. interfector it does not reach the mesopleural margin. The placement of this fossil in extinct or extant Hymenoptera families is dubious. Bryopompilus interfector is considered herein as a member of a new fossil family Bryopompilidae . This fossil has a rounded posterior lobe on the pronotum, which resembles the lobe observed in Apoidea. Nevertheless, this lobe is deeply incised and overlaps the wing base both above and below, whereas in Apoidea it is entire, rounded, and somewhat inflated, and only extremely rarely reaches the wing base and never overlaps it from above.

The age of Burmese amber has been assigned to the late Albian (106 to 100 Ma) based on palynology, insect and ammonite inclusions ( Ross et al. 2010). A more recent study places the deposits in the early Cenomanian (ca. 98 Ma) using U-Pb zircon dating ( Shi et al. 2012).

Stratigraphic and geographic range.— Kachin state of Burma, early Cenomanian Burmese Amber.