Tachydromiini (Sinclair & Cumming, 2006)

Key to fossil genera of Tachydromiini View in CoL and Cretoplatypalpus group

Remarks. We have included Symballophthalmus (tribe Symballophthalmini ) in the key because fossil records of this primitive genus are highly likely. The key somewhat suffers from fragmented data in some genera, as noted.

1 Scutellum with at least 6 setae. Prosternum usually separated from proepisternum (unknown state in Mesoplatypalpus View in CoL and Electrocyrtoma )...................................................................................... 2

– Scutellum with at most 4 setae. Prosternum usually fused with proepisternum (except Archiplatypalpus View in CoL )................ 6

2 Wing with cell cua. Eyes holoptic or dichoptic …............................................................ 3

– Wing without cell cua. Eyes dichoptic (unknown state in male of Mesoplatypalpus View in CoL )................................ 5

3 Wing cuneiform; crossvein bm-m at most slightly oblique, touching crossvein r-m ( Chvála 1975: fig. 23). [Additional character: eyes holoptic.] Extant genus, no known fossils......................................... Symballophthalmus Becker View in CoL

– Wing at apex of cell br as broad as at middle; crossvein bm-m strongly oblique, relatively broadly separated from crossvein r-m................................................................................................ 4

4 Wing with cell cua extending nearly to middle of cell bm ( Kovalev 1978: fig. 1b; Grimaldi & Cumming 1999: fig. 34). Eyes dichoptic. Scutellum with 6 setae. Mesozoic: Upper Cretaceous, Russia, Taimyr and Cedar Lake, Manitoba............................................................................................. Cretoplatypalpus Kovalev View in CoL

– Wing with cell cua extending far beyond middle of cell bm ( Cockerell 1917: fig. 5). Eyes probably holoptic. Scutellum with more numerous setae. Mesozoic: mid-Cretaceous, Burmese amber.......................... Electrocyrtoma Cockerell

5 Costal vein ending just slightly past apex of vein R 4+5 ( Grimaldi & Cumming 1999: fig. 35). Scutellum with 8 setae. Mesozoic: Upper Cretaceous, Cedar Lake, Manitoba .................................. Mesoplatypalpus Grimaldi & Cumming View in CoL

– Costal vein ending at apex of vein M 1. Scutellum with 6 setae. Cenozoic: middle Eocene, Sakhalinian amber............................................................................................. Eoplatypalpus gen. nov.

6 Eyes holoptic ( Kovalev 1974: fig. 1). Prosternum separated from proepisternum. Mesozoic: Upper Cretaceous, Russia, Taimyr......................................................................... Archiplatypalpus Kovalev View in CoL

– Eyes dichoptic. Prosternum fused with proepisternum........................................................ 7

7 Wing cell cua more or less formed, with vein CuA distinct and vein CuA+CuP present, although sometimes faint ( Chvála 1975: fig. 24). Eyes with upper margins closer to level of ocellar tubercle, divergent near ocellar tubercle with distance between eyes wider than frons ( Sinclair et al. 2023: fig. 9C). Mid leg usually raptorial, with femur thickened and armed with two rows of spine-like setae ventrally, tibia often ending in sharp spur. Extant genus; Cenozoic: upper Eocene, Baltic amber............................................................................................. Platypalpus Macquart View in CoL

– Wing cell cua absent (vein CuA+CuP absent); vein CuA usually present (sometimes absent in recent species) ( Chvála 1975: fig. 26). Eyes with upper margins extending far beyond ocellar tubercle, slightly convergent or parallel behind ocellar tubercle with distance between eyes usually slightly narrower than frons ( Sinclair et al. 2023: fig. 8A). Mid leg simple, at most with some modifications in male (subbasal clusters of spine-like setae, excavations and tubercles). Extant genus; Cenozoic: uppermost Eocene, shales of Florissant Formation, Colorado, USA; upper Eocene, Baltic amber................. Tachypeza Meigen View in CoL