A new find of Early Cretaceous radiolarians on the Arctic coast of East Siberia (Lena River delta area)

The Jurassic-Cretaceous boundary in Boreal Russia: radiolarian and calcareous dinoflagellate potential biomarkers

“…Radiolarian col lec tions were taken from 6 sec tions of the Rus sian Arc tic (Vishnevskaya and Kozlova, 2012), 7 sec tions in the Si be rian Bashenovo For ma tion (Panchenko et al, 2016), as well as the Lena Delta sec tion (Vishnevskaya et al, 2014) and 24 pro files in NE Asia Filatova, 2012, 2016). The num ber of spec i mens ex am ined ex ceeds one thousand: 44 sam ples come from 6 sec tions of the Rus sian Arc tic, 700 sam ples from 7 sec tions in the Si be rian Bashenovo Suite and the Lena Delta sec tion, and 300 sam ples from 24 pro files in NE Asia.…”

“…aculeatum Bragin, Parviciungula alata Kozlova and Vishnevskaya, P. papulata Kozlova and Vishnevskaya, Praepar vicingula ro tunda Hull, and Spinicingula cf. ceratina Kozlova and Vishnevskaya (Vishnevskaya et al, 2014).…”

“…The third cli ma tic radiolarian as so ci a tion, a Boreal one, is char ac ter ized by the prev a lence of Parvicingula and is more typ i cal of high lat i tudes (Pa cific Rim, Ar gen tina, (1993,2009) north ern Eu ro pean and Si be rian plat forms). This as so ci a tion is wide spread in the Volga River Ba sin of the Rus sian Plat form (Vishne vskaya and Bara boshkin, 2001;Vishnevskaya and Kozlo va, 2012) and many ar eas of West ern Si be ria (Vishnevskaya, 1998(Vishnevskaya, , 2013Bragin, 2009;Vishnevskaya et al, 2014). The ge nus Parvicin gula is also wide spread in the Arcto-Bo real prov ince (Spitsbergen, Timan-Pechora Ba sin, Nor way Sea and north ern Si be ria; Vish ne vskaya and Kozlova, 2012) and Aus tral prov ince of Antarcti ca and the In dian Ocean (site 765, 766 and DSDP site 261, Argo Abys sal Plain and Lower Exmouth Pla teau; Kiessling, 1999).…”

“…The ubiq ui tous pres ence of the Ju ras sic-Early Cre ta ceous gen era Parvicingula and Praeparvicingula [Parvicingula blowi Pessagno, P. jonesi Pessagno, P. excelsa Pessagno and Blome, P. blomei Yang, Praeparvicingula holdsworthi (Yang), Praeparvicingula aff. sencilla Hull] in radiolarian as so ci a tions of the Anyui Ocean Filatova, 2012, 2016), Bazhenovo (Panchenko et al, 2015), Pechora and Rus sian seas (Vishnevskaya and Kozlova, 2012) sup ports the pres ence of the north ern sea way bring ing a large num ber of spe cies of these gen era from the Pa cific palaeoclimatic prov ince to the Bo real, Arc tic (Bragin, 2011;Vishnevskaya et al, 2014) and Arcto-Bo real of the north At lan tic (Vishnevskaya and Kozlova, 2012). Only in the later Berriasian (at the end of the Volgian) time, new spe cial ized gen era -Arctocapsula, Echinocampe, Nordvikella and Spinicingula -ap peared in radiolarian as so ci ations (Bragin, 2011;Vishnevskaya and Kozlova, 2012).…”

“…Typ i cal Mid dle-Late Volgian (Mid dle Tithonian-Berriasian) radio lar ians have been de scribed from Nordvik of the Arc tic coast of east ern Si be ria (Zakharov and Rogov, 2006;Bragin, 2011) and Lena River Delta area (Vishnevskaya et al, 2014), where spe cies of the en demic fam ily Echinocampidae Bragin pre vail in the Lower Cre ta ceous (Fig. 8).…”