Coleoptera from the middle-upper Eocene European ambers: generic composition, zoogeography and climatic implications

Abstract

The paper contains a review of coleopteran genera known from Baltic, Bitterfeld and Rovno amber localities. Altogether 420 genera (191 extinct and 229 extant) from 78 families are listed from these three Lagerstätten (as of 7 March 2017). The listed beetles were analyzed zoogeographically and distributional maps for 72 genera were compiled. One-quarter (56) of the genera that have survived since the Eocene have cosmopolitan ranges at present; 35 extant genera have been extripated from the Palaearctic since the Eocene. Approximately 40% of beetle genera from the middle-upper Eocene European ambers can be encountered in the wild in present-day Europe, while 5 of these genera are supposed to be European relict endemics originating in Fennosarmatia. The general similarity of the Baltic amber (s.l.) beetle assemblage to modern south Palaearctic fauna is the strongest, the Nearctic elements are more numerous in the middle-upper Eocene European ambers than the Oriental taxa. The simplified Mutual Climatic Range (MCR) method was used for palaeoclimate reconstruction based on fossil beetles. The coleopteran assemblage of Baltic amber is interpreted as indicative of warm temperate, humid, equable climate with reduced thermal seasonality [annual average temperatures range from +10–20˚C; mean of the coldest month temperatures around +10˚C; mean of the hottest month temperature around +20–24˚C; annual precipitation around 750–1500 mm]. The primary importance of high humidity for existence of the Eocene biota is pointed out.

A new fossil soldier beetle (Coleoptera: Cantharidae) of the genus CacomorphocerusSchaufuss, 1892 from Baltic amber

“…Inclusions of fossil Cantharidae in amber are fairly common (Spahr 1981;alekSeev 2013alekSeev , 2017Fanti 2017a) with the first species described by SchauFuSS (1892), and later extinct lineages at the tribal level described by kazantSev (2013) and Fanti & kupryjanowicz (2018). Various taxa of Cantharidae were described from Baltic, Rovno, Mexican (Chiapas) and Burmese amber as well as from the Brunstatt brown coals of Alsace.…”

New fossil cylindrical bark beetle (Zopheridae: Colydiinae: Gempylodini) from Eocene Baltic amber: An abnormal or intermediate form within Tenebrionoidea

“…Before the current study, eight fossilized Baltic amber species from five genera of zopherids belonging to Synchitini Erichson, 1845 (six spe-cies), and Pycnomerini Erichson, 1845 (two species), were described (Alekseev, 2017;Bukejs et al, 2019). All of these taxa were comparatively easily assigned to Recent genera and do not display any especially peculiar characters.…”

Catalogue and composition of fossil Anthicidae and Ischaliidae (Insecta: Coleoptera)

“…Klebs, 1910: as Mactratria [sic! ];Bachofen-Echt, 1949;Abdullah, 1964;Larsson, 1978;Spahr, 1981;Poinar, 1992;Kirejtshuk, 2002Telnov, 2012b;Alekseev, 2017 Baltic Notoxus sp. Hope, 1836;Helm, 1896;Handlirsch, 1907;Larsson, 1978;Spahr, 1981;Poinar, 1992;Kirejtshuk, 2002 Baltic rensmeyer and Turner, 2013-2018).…”

“…Tomoderinae Bonadona, 1961 Tomoderus sp. Klebs, 1910;Bachofen-Echt, 1949;Abdullah, 1964;Larsson, 1978;Spahr, 1981;Poinar, 1992;Kirejtshuk, 2002Telnov, 2012aTelnov, , 2013Alekseev, 2017 Baltic (Abdullah, 1969;Chandler, 2010). The subfamily Eurygeniinae is less diverse than the Anthicinae in terms of genera and species, but also reveals a cosmopolitan distribution (Chandler, 2010 Oriental (E India, most of continental Southeast Asia, and Greater Sunda Islands) regions (Gusakov and Telnov, 2007;Young, 2011;Alekseev and Telnov, 2016).…”