Tropical and Holarctic Ants in Late Eocene Ambers

Abstract

Based on representative collections, the ratio of tropical and Holarctic ant species in Priabonian (Late Eocene) Baltic, Bitterfeld (Saxonian), Danish and Rovno ambers is analyzed for the first time. In surveyed representative collections of Baltic amber, the ratios of Holarctic and tropical ant species are from 1.1 to 1.5; with 10 Holarctic and 9 tropical species (out of 31) in the PIN-964 collection, and 9 and 5 species (out of 29) in the Giecewicz collection; the ratio in the representative collection of Saxonian amber is 0.9, 11 Holarctic species vs. 12 tropical species (out of 55); in the representative collection of Rovno amber it is 0.65, 15 vs. 23 species (out of 79); and in the representative collection of Danish amber it is 0.64, 7 vs. 11 species (out of 36). Hence, in representative collections of Baltic amber, Holarctic species clearly prevail not just in terms of the share of their specimens (by 9.8 to 19.6 times), but also by the number of species. In Bitterfeld amber, Holarctic species are somewhat less numerous than tropical ones, but their specimens are 6 times greater. In representative collections of Rovno and Danish ambers, the number of Holarctic species is 1.5 to 1.7 times smaller than that of tropical species, but the number of their specimens is 4.9 to 6.9 times greater. The numbers of tropical and Holarctic species represented by more than one specimen is similar in Priabonian ambers, 25 versus 22, but Holarctic species include four dominants or subdominants. The abundance of temperate elements in the Priabonian amber ant fauna along with the relatively small number of tropical elements greatly distinguishes it from the Middle European Lutetian ant faunas of Messel and Eckfeld in shale, which do not have temperate elements at all. Formica phaethusa Wheeler, Glaphyromyrmex oligocenicus Wheeler, Plagiolepis squamifera Mayr, Proceratium eocenicum Dlussky, Hypoponera atavia (Mayr), Ponera lobulifera Dlussky, Aphaenogaster mersa Wheeler, and Ennaemerus reticulatus Mayr are new records for Rovno amber, and Formica gustawi Dlussky and Gnamptogenys europaea (Mayr) for Danish amber.

Comparison of Biting Midges of the Early Eocene Cambay Amber (India) and Late Eocene European Ambers Supports the Independent Origin of European Ambers

“…Th e absence of this genus in the Baltic amber of the Gdańsk Bay can be explained by climatic factors, as well as the absence in this amber of the equally easily identifi able myrmicine genus Fallomyrma Dlussky et Radchenko. Th e latter genus is very common in Danish amber (6.9 % of all ants: Perkovsky, 2011) and much more abundant and diverse than previously believed in Rovno amber, in which one-third of all myrmicines belong to four species of this genus (Perkovsky, 2016).…”

“…Earlier it was found that in the Baltic amber, Holarctic ant species clearly prevail not just in terms of the share of their specimens (by 9.8 to 19.6 times), but also by the number of species (Perkovsky, 2016). In Bitterfeld amber, Holarctic ant species are somewhat less numerous than tropical ones, but their specimens are 6 times more numerous than tropical ones (Perkovsky, 2016).…”

“…Earlier it was found that in the Baltic amber, Holarctic ant species clearly prevail not just in terms of the share of their specimens (by 9.8 to 19.6 times), but also by the number of species (Perkovsky, 2016). In Bitterfeld amber, Holarctic ant species are somewhat less numerous than tropical ones, but their specimens are 6 times more numerous than tropical ones (Perkovsky, 2016). In unbiased collections of Rovno and Danish ambers, the number of tropical ant species is 1.5 to 1.7 times as high as of Holarctic species, but the number of their specimens is 4.9 to 6.9 times less (Perkovsky, 2016) .The only difference from the results obtained earlier for ants, apart from the fact that Holarctic biting midges dominate over tropical ones in Danish amber in the number of species is the surprisingly high proportion of Holarctic components in the unbiased HMB collection.…”

“…In Bitterfeld amber, Holarctic ant species are somewhat less numerous than tropical ones, but their specimens are 6 times more numerous than tropical ones (Perkovsky, 2016). In unbiased collections of Rovno and Danish ambers, the number of tropical ant species is 1.5 to 1.7 times as high as of Holarctic species, but the number of their specimens is 4.9 to 6.9 times less (Perkovsky, 2016) .The only difference from the results obtained earlier for ants, apart from the fact that Holarctic biting midges dominate over tropical ones in Danish amber in the number of species is the surprisingly high proportion of Holarctic components in the unbiased HMB collection. In the Manfred Kutsher collection the ratio of Holarctic and tropical biting midge specimens is only 3.6, which is only 0.43 times as high as in HMB.…”

Who’s that girl? A singular Tropiduchidae planthopper from the Eocene Baltic amber (Hemiptera: Fulgoromorpha)

“…(Archibald and Farrell, 2003;Archibald et al 2013;Szwedo, 2012;Szwedo and Kania, 2015;Wolfe et al, 2016). Palaeoclimatic and palaeoecological interpretations result in many questions regarding the variability of Baltic amber forest(s) habitats and environments (e.g., Alexeev and Alexeev, 2016;Perkovsky, 2016;Sadowski et al, 2016aSadowski et al, , 2016bSchmidt et al, 2016;Alexeev, 2017). However, it is probable that dry and open habitats, as e.g., sparse and open forests or low vegetation areas with a few resiniferous trees or at least on borderland with amber producing trees, were present in the area and at time of the Baltic amber deposit alimentation (Kohlmann-Adamska 2001; Szwedo, 2012;Szwedo and Drohojowska, 2015).…”