Eastern Paratethyan Turritellidae biodiversity

Popov (1986) provided a first overview of most of the data from the eastern Paratethys, where Neogene Turritellidae were restricted to the early and middle Miocene. The Miocene of the Eastern Paratethys is divided into several regional stages (Popov et al. 2004; Gozhyk et al. 2015) (Fig. 2). The earliest Turritellidae records are listed by Popov (1986) from the Sakaraulian (~Eggenburgian), comprising Turritella turris de Basterot and Peyrotia desmarestina de Basterot. In addition, Gamkrelidze et al. (1964) mentioned Turritella vermicularis Brocc. var. lineolatocincta Sacco from the Sakaraulian of Georgia. In the Central Paratethys, this taxon was based on misidentifications of other species. Therefore, it remains unclear which species was found in Georgia.

No Turritellidae are known so far from the Kotsakhurian (~Ottnangian and partly Karpatian), probably due to the endemic character of the respective faunas (Iljina 1993). Turritellidae appear again during the Tarkhanian (late Karpatian and early Badenian) with Turritella pythagoraica Hilber (= A. indigena), Turritella cf. vermicularis (Brocchi), Turritella tricincta Borson, and Turritella turris along with the endemic T. sokolovi Mikhailovsky, 1903 . A record of the otherwise exclusively Oligocene Turritella strangulata Grateloup, mentioned by Alizade et al. (1980) from Nakhchivan, is most probably a misidentification. In addition, Popov (1986) mentioned an Allmonia species (as Protoma cathedralis quadricincta Schaffer) from the Tarkhanian of the northern Talysh in Azerbaijan.

During the Chokrakian and Karaganian (late Langhian, middle Badenian), Turritellidae declined again in the eastern Paratethys. The few findings suggest reworking from older strata (Popov, 1986), which would also explain the erratic stratigraphical occurrence of otherwise early Miocene T. terebralis Lamarck, T. gradata Menke, and T. desmarestina de Basterot from the Chokrakian of Azerbaijan, mentioned by Alizade et al. (1980) and Popov (1986). Only T. pythagoraica Hilber (= A. indigena) and T. bicarinata Eichwald might be autochthonous elements. The Konkian faunas (early Serravallian, late Badenian) reflect a slight rise in Turritellidae diversity with T. pythagoraica Hilber (= A. indigena), T. spirata (Brocchi), and Turritella bicarinata Eichwald. The Turritellidae vanished with the onset of the Sarmatian.

All these records and identifications will need revision, and herein we have just reproduced the names proposed by Popov (1986). In total, only two species have been described from the Eastern Paratethys as new species: Turritella sokolovi Mikhailovsky, 1903, from the Tarkhanian of Tomakivka (Oblast Dnipropetrovsk, Ukraine) and Turritella atamanica Bogachev, 1895, from the Tarkhanian of Novocherkassk (Oblast Rostow, Russia). Turritella sokolovi might represent a subjective junior synonym of A. carpathica, and Turritella atamanica is most probably a subjective junior synonym of A. indigena (Popov 1986; herein).

Concluding, Archimediella indigena (Eichwald, 1830) (= T. pythagoraica Hilber, 1882), Oligodia bicarinata (Eichwald, 1830), Oligodia spirata (Brocchi, 1814), Helminthia tricincta (Brocchi, 1814) and probably Helminthia vermicularis (Brocchi, 1814) and Archimediella carpathica are common taxa during the middle Miocene in the Eastern Paratethys. Of these, only A. indigena is endemic to the region and the adjacent Polish-Ukrainian Carpathian Foreland Basin. All other taxa suggest immigration of Proto-Mediterranean species via the Central Paratethys.