taxonID	type	description	language	source
8C00744CFFEC2679B1ED7CA8FD6A00FC.taxon	description	Finally, we find it difficult to attribute fossil	en	Radchenko, A. G., Perkovsky, E. E. (2021): Wheeler’s dilemma revisited: first Oecophylla-Lasius syninclusion and other ants syninclusions in the Bitterfeld amber (late Eocene). Invertebrate Zoology 18 (1): 47-65, DOI: 10.15298/invert-zool.18.1.05
8C00744CFFEC2679B1ED7CA8FD6A00FC.taxon	description	Already Wheeler (1915) reported 10 ant syninclusions from Baltic amber and stressed that “ simultaneous inclusion could only have occurred in the case of forms living at precisely the same time and place ” (op. cit.: 15). Though they did not include a mix of definitely tropical and Holarctic ant genera, five syninclusions with Ctenobethylus goepperti (Mayr, 1868) containHolarctic Dolichoderustertiarius (Mayr, 1868), Myrmica rudis (Mayr, 1868), Lasius schiefferdeckeri Mayr, 1868, Formica flori Mayr, 1868 and Cataglyphoides constrictus (Mayr, 1868), while two other include C. goepperti with tropical Yantaromyrmex geinitzi (Mayr, 1868) and Gesomyrmex hoernesi Mayr, 1868 (names of species and genera are given according to modern taxonomy). The remaining three syninclusions contain only Holarctic or only tropical genera. More than 60 ant syninclusions are known in late Eocene European ambers, including those with L. schiefferdeckeri reported by Dlussky (2011); 20 of these are from Bitterfeld amber (Dlussky, pers. comm., 2013) (Table 1). Five syninclusions from Bitterfeld amber contain both tropical and Holarctic ants: two of	en	Radchenko, A. G., Perkovsky, E. E. (2021): Wheeler’s dilemma revisited: first Oecophylla-Lasius syninclusion and other ants syninclusions in the Bitterfeld amber (late Eocene). Invertebrate Zoology 18 (1): 47-65, DOI: 10.15298/invert-zool.18.1.05
8C00744CFFEF2677B1ED7988FBC8037E.taxon	description	The ratio of Holarctic and tropical taxa is important for a better understanding the climatic conditions in amber forests and the age of amber biota as a whole. After adding Aphaenogaster, Temnothorax, C. mengei, Eocenomyrma and N. pygmaea the ratio of Holarctic to tropical s. l. elements for representative collections is 2.8 – 3.5 for Baltic amber, 1.6 for Danish amber and 2.1 for both Bitterfeld and Rovno ambers (Table 2). It is interesting that at least for two amber faunas with the same (Danish, 1.6) or very similar (Rovno, 1.9) ratios were calculated for biting midges (Ceratopogonidae): predominance of Holarctic biting midges in the representative collections from other ambers is even higher than for Holarctic ants (Perkovsky, 2017). In the early Eocene at Messel and middle Eocene at Eckfeld, tropical taxa absolutely dominate, nearly as much as in tropical climate Oligocene Sicilian amber (Emery, 1891; Wappler, 2003; Dlussky et al., 2008, 2009; Archibald et al., 2011; Dlussky, 2012; Dlussky, Wedmann, 2012). The prevalence of Holarctic species in all representative amber ant collections is associated with decreasing of temperature in the late Eocene (see below). The ratio of Holarctic and tropical specimens in the former private amber ant collection of M. Kutscher from Bitterfeld amber (now in the collection of Geowissenschaftlicher Zentrum der Georg-August-Universität Göttingen) is only 0.98, but it is highly biased, containing mainly rare and ‘ exotic’ ants (Dlussky, Rasnitsyn, 2009).	en	Radchenko, A. G., Perkovsky, E. E. (2021): Wheeler’s dilemma revisited: first Oecophylla-Lasius syninclusion and other ants syninclusions in the Bitterfeld amber (late Eocene). Invertebrate Zoology 18 (1): 47-65, DOI: 10.15298/invert-zool.18.1.05
