Type material: Holotype male, RUSSIA, Krasnoyarsk region, Podkamennaya Tunguska River, middle course of Yenisey River (61.6 ºN 90.1 ºE – 60.9 ºN 101.9 ºE), 9.vii. 1921, leg. A. Tugarinov (ZIN).
Note on the type-locality: The Podkamennaya Tunguska (= Stony Tunguska) River has a length of 1870 km, but the type-locality of C. sibirica can be narrowed down. The collector A.Tugarinov is known through his investigations of the famous Tunguska Explosion. All through the summer of 1921,Tugarinov worked with the Tunguska Explosion expedition, so the fly was collected somewhere between the mouth of the Podkamennaya Tunguska and the place of Tunguska Explosion, that is from 61.6 ºN 90.1 ºE to 60.9 ºN 101.9 ºE (N.E. Vikhrev, pers. comm.).
Material examined: 1 male, RUSSIA, Wrangel Island, Somnitel’nye Mts, 71 º00’N 179 º 32 ’W, 14.vii– 15.viii. 2006, leg. O. Khruleva (SZNM). 3 males, Russia, Taymyr Peninsula, cordon Ary-Mas, 72.5 ºN 101.94 ºE, 10–12.vii. 2010, leg. A. Barkalov (1 male in ZMUM, rest in SZNM).
Habitats: Sand and pebbles on a river floodplain with a mixture of grass-cereal-willow-moss cover (Fig. 1 F).
Method of capture: Pitfall traps.
Distribution: This species has not been collected since Hennig described it. Only one locality was known for Coenosia sibirica (Russia: Podkamennaya Tunguska River). Wrangel Island and the Taymyr Peninsula are new northern localities for this species.
Comments: This species should be incorporated in other couplets into the recent key to Siberian Coenosia (Sorokina, 2009 a: 6):
28 Two pairs of presutural dorsocentral setae, the anterior pair about half as long as posterior pair....................... 29 - Only one pair of presutural dorsocentrals................................................................. 31 a 29 Hind femur only in distal third with 2 long anteroventral setae, and one long posteroventral seta at middle; mid and hind femora predominantly yellow, only with a weak brownish subapical ring; terminalia as in Figs. 6 A, 6 I...... C. sibirica Hennig - Femur with full rows of long and strong anteroventrals and posteroventrals; mid and hind femora black at least in distal half.................................................................................................... 30 30 Couplet as in Sorokina (2009 a)
31 a Fore femur yellow with a brownish-black dorsal streak; hind femur only in distal third with 2 long anteroventral setae; mid femur with three long posteroventrals in basal half, of which the seta near the middle is longer and stronger..................................................................................................... C. sibirica Hennig - Fore femur predominantly dark; hind femur with full rows of long anteroventrals; mid femur with one long posteroventral in basal half........................................................................................... 31 31 Couplet as in Sorokina (2009)