Review of Palaeobotany and Palynology 201 (2014) 29–40

Contents lists available at ScienceDirect

Review of Palaeobotany and Palynology

j ourna l homepage: www.e lsev ie r .com/ locate / revpa lbo

Research paper

Distribution and biostratigraphical significance of Heterosphaeridiumbellii sp. nov. and other Late Cretaceous dinoflagellate cysts from thesouthwestern Barents Sea

Wiesława Radmacher a,b,⁎, Jarosław Tyszka a, Gunn Mangerud b

a ING PAN — Polish Academy of Sciences, Institute of Geological Sciences, Kraków Research Centre, BioGeoLab, ul. Senacka 1, 31-002 Kraków, Polandb Department of Earth Science, University of Bergen, Postbox 7800, NO-5020 Bergen, Norway

⁎ Corresponding author at: ING PAN, OBK, ul. SenacTel.: +48 667965621.

E-mail addresses: ndkrol@cyf-kr.edu.pl (W. Radmache(J. Tyszka), Gunn.Mangerud@geo.uib.no (G. Mangerud).

0034-6667/$ – see front matter © 2013 Elsevier B.V. All rihttp://dx.doi.org/10.1016/j.revpalbo.2013.10.003

a b s t r a c t

a r t i c l e i n f o

Article history:Received 11 March 2013Received in revised form 10 October 2013Accepted 28 October 2013Available online 6 November 2013

Keywords:palynologydinoflagellate cystBarents SeaCampanian

A palynological study of the Upper Cretaceous Kveite Formation and Lower Palaeogene Torsk Formation in twoexploration wells from the southwestern Barents Sea is presented. The investigation has revealed an intervalcharacterised by the acme of a new dinoflagellate cyst species Heterosphaeridium bellii sp. nov. Its calibration toa comparable Heterosphaeridium event in ammonite-dated strata from the Western Interior Basin of NorthAmerica supports the Late Campanian age. An emendation of Heterosphaeridium heteracanthum is provided inorder to emphasize the differences between both Heterosphaeridium species. The Turonian to Coniacian age isbased on the last common occurrence (LCO) of Heterosphaeridium difficile and the last occurrence (LO) ofStephodinium coronatum. The Early Campanian is established based on the last occurrence of Callaiosphaeridiumasymmetricum, Chatangiella bondarenkoi and Palaeoglenodinium cretaceum. The Late Campanian to EarlyMaastrichtian age is suggested by the last common occurrence of the new species H. bellii, the last occurrenceof Odontochitina operculata and common occurrence of Spongodinium delitiense. The last occurrence ofRaetiaedinium truncigerum occurs within this interval coinciding with the last super abundant occurrence(LSAO) of H. bellii sp. nov. The palynological events are put alongside geophysical logs to check the validity ofthe correlation. The study documents several hiatuses, indicating that Upper Cenomanian, Santonian, MiddleCampanian, Upper Maastrichtian and lowermost Palaeocene strata are missing in well 7120/7-3, whereas strataof Upper Cenomanian to Santonian and UpperMaastrichtian to lowermost Palaeocene age seem to bemissing inwell 7119/9-1. The interval represented by the acme of the new gonyaulacacean species H. bellii is consideredhere to be a useful Late Campanian biostratigraphic marker horizon.

© 2013 Elsevier B.V. All rights reserved.

1. Introduction

Due to major uplift and erosion, Upper Cretaceous strata are notpresent on Svalbard (Birkenmajer, 1981; Dallmann, 1999; Worsley,2008) and occur only in some depocentres in the Barents Sea. Few pal-ynological studies have been published from the Upper Cretaceous suc-cession in the Norwegian Arctic although hydrocarbon explorationwells are known to have penetrated the strata. A brief description ofthe Campanian dinocyst assemblage from the southwestern BarentsSea was provided by Nagy et al. (1997). However, this study mostly fo-cuses on the foraminifera, diatoms and dinoflagellate cysts of thePalaeogene Torsk Formation. Williams et al. (2005) included aMaastrichtian toCampanian section fromwell 6707/10-1 in theNorwegianSea, providing discussion on non-acid palynological preparation tech-niques. A more regional overview was published by Costa and Davey

ka 1, 31-002 Kraków, Poland.

r), ndtyszka@cyf-kr.edu.pl

ghts reserved.

(1992) for the Norwegian North Sea. Gradstein et al. (1999) provided pal-ynological information on the latest Cretaceous and Palaeogene of the Cre-taceous seaway between Norway and Greenland, whereas the LateCretaceous and Palaeogene from offshore Norway are available online atthe Norwegian Interactive Offshore Stratigraphic Lexicon (NORLEX)website (Gradstein et al., 2010). Additional information on Late Cretaceouspalynofloras of the Arctic region has been obtained from southern EastGreenland (Nøhr-Hansen, 2012), West Greenland (Nøhr-Hansen, 1993a,b, 1994, 1996; Nøhr-Hansen and Dam, 1997) and Northern Siberia(Lebedeva, 2006).

Two exploration wells, 7119/9-1 and 7120/7-3, drilled respectivelyby ELF PetroleumNorge AS and Statoil in the Tromsø Basin, were studiedin order to reveal the palynological succession from this area and estab-lish relative ages based on dinoflagellate cysts. Reliable correlation toolsare critical for the petroleum industry and palynology has proved to bean essential method for the correlation and dating of exploration wells.Themain objective of this study is to assess the stratigraphic significanceof Late Cretaceous dinoflagellate cysts based on analyses from the twoexploration wells. The present paper focuses on the description ofHeterosphaeridium bellii sp. nov., a dinoflagellate cyst species occurring

30 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

abundantly in parts of the succession, and is followed by documentationand discussion of the recorded dinocyst events. The acme of the newspecies represents a significant and characteristic event for biostrati-graphic correlations and palaeoenvironmental interpretations. An emen-dation of the Heterosphaeridium heteracanthum diagnosis is provided inorder to add detailed information and stress differences that are neces-sary for distinguishing it from other Heterosphaeridium species.

Recently, foraminiferal studies from adjacent high latitude areas in-cluding the Barents Sea, the Vøring Basin and the Arctic LomonosovRidge have been published (Kaminski et al., 2009; Setoyama et al.,2011a,b,c, 2013), showing limited biostratigraphic application. The fora-miniferal assemblages present in that region are characterised by theabsence of species of high biostratigraphical value (Setoyama et al.,2013). In contrast, foraminiferal morphogroup analysis is important inorder to understand the palaeoenvironment and palaeobathymetry ofthe basin. Dinoflagellate cysts are used in this paper for biostratigraphicdating, giving a relative age for the studied sections.

2. Geological background

The Norwegian Sea and the Barents Sea areas were tectonised bymajor continental collisions and complex rifting processes (Doré, 1991;Faleide et al., 1993; Ren et al., 2003) that eventually lead to continentalbreak-up, causing the formation of the Norwegian-Greenland Sea andthe Arctic Ocean. Additionally, a large part of the northern Barents Seawas affected by uplift and subjected to widespread erosion, which wasintensified by probable bottom water currents, having a local influenceon the Late Cretaceous to Early Palaeogene hiatus in the region (Nagyet al., 1997; Setoyama et al., 2011a). In Svalbard, Palaeogene sedimentsrest directly on the Lower Cretaceous deposits and theUpper Cretaceousrecord is missing completely (Birkenmajer, 1981; Dallmann, 1999;Worsley, 2008). In contrast, Upper Cretaceous strata of variable thick-ness are present in the Barents Sea (Kelly, 1988; Faleide et al., 1993;Nagy et al., 1997). However, they are often discontinuous, causing theirinternal structure to be difficult to interpret.

This study focuses mainly on the Upper Cretaceous succession fromthe Ringvassøy–Loppa Fault Complex located at the border between the

Fig. 1.Map of the southwestern Barents Sea sh

Tromsø Basin and the Hammerfest Basin (Fig. 1). During the Late Creta-ceous the Hammerfest Basin was relatively stable with limited Creta-ceous subsidence caused by local tectonics (Faleide et al., 1993). Incontrast, the Tromsø Basin was subjected to intense Cretaceous subsi-dence and sedimentation, resulting in a thick Upper Cretaceous sedi-mentary record.

The lithostratigraphical scheme of the southwestern Barents Sea hasbeen formally defined byWorsley et al. (1988). The studied successionscomprise the Upper Cretaceous Nygrunnen Group and PalaeogeneSotbakken Group. The Nygrunnen Group is represented by the KveiteFormation, which contains greenish-grey to grey shale and claystonewith thin interbeds of limestone and siltstone. The Kveite Formationthickness ranges to over 1200 m in the centre of the Tromsø Basin, butbecomes thinner eastwards, towards the Hammerfest Basin, where itsequivalent, the Kviting Formation is less than 50 m thick. The KvitingFormation is more sand-prone and can be found in the eastern part ofthe Hammerfest Basin (Worsley et al., 1988; Faleide et al., 1993). TheSotbakken Group is represented by the Torsk Formation, comprisinggreenish-grey claystones with tuffaceous horizons in the lower part(Fig. 2).

3. Materials and methods

A total of 44 palynological slides prepared fromditch cutting samplesfrom two exploration wells in the southwestern Barents Sea wereanalysed. The slides fromwell 7119/9-1were supplied by theNorwegianPetroleum Directorate in Stavanger. Samples from well 7120/7-3 wereprovided by Statoil and processed in the Laboratory of Palaeobotanyand Palynology of Utrecht University in the Netherlands, according totheir standard palynological procedure. This comprises removal of con-taminants, crushing the samples, removal of carbonates and silicateswith HCL and HF, removal of large particles by sieving with 250 μmand small particles with a 15 μm sieve, separation of organic materialusing heavy liquid and preparation of slides. The average sampling inter-val was 10 m, with the exception of parts in well 7119/9-1, where someof the palynological slides were not available for analysis (see Fig. 3).Where possible, two hundred dinoflagellate cyst specimens were

owing location of the studied boreholes.

Fig. 2.Upper Cretaceous and Palaeocene lithostratigraphy of the southwesternBarents Sea.Modified after Worsley (2008) and Gradstein et al. (2012).

31W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

counted per sample, using a Carl Zeiss Axio Imager.A2 Microscope. Lightphotographs were taken by AxioCam ERc5s at the Department of EarthScience, University of Bergen, Norway. The semi-quantitative analysisillustrated in Figs. 3 and 4 has been applied as follows: LO: last occur-rence (4 or fewer specimens), LCO: last common occurrence (5 to 20),LAO: last abundant occurrence (21 to 80), LSAO: last super abundant oc-currence (81 to 150) and acme (for the greatest numerical abundance).The sample positions and relative abundance of all species are illustratedin range charts (Tables 1 and 2). The systematics follow Fensome et al.(2008b) and Fensome et al. (2009).

4. Results

An interval dominated by a distinctive dinocyst species comparableto Heterosphaeridium heteracanthum Deflandre and Cookson, 1955(sensu Eisenack and Kjellström, 1971) was identified in the Kveite

Formation in both wells. This species is widely known in the hydrocar-bon industry by the following three names: Cleistosphaeridium sp. 1,Heterosphaeridium cf. heteracanthum or Heterosphaeridium sp. A. Thegenus Heterosphaeridium was originally described as having solid pro-cesses of varying widths, whereas the processes in Cleistosphaeridiumwere only described as closed distally. A synopsis of Cleistosphaeridiumin 1978 indicated that Cleistosphaeridium has processes of similar sizeand shape. The genus Heterosphaeridium was not emended before thepublication by Yun (1981), who included forms characterised by thepresence of two or more types of processes. The process style inHeterosphaeridium bellii sp. nov. described below is relatively simple and“Cleistosphaeridium-like”, but differs in the presence of solid and hollowprocesses in one specimen. Therefore, prior to 1981, Cleistosphaeridiumwould have been themost likely place for it. The new species and its tax-onomic issues are described below.

4.1. Systematic palaeontology

Division: DINOFLAGELLATA (Bütschli, 1885) Fensome et al., 1993Subdivision: DINOKARYOTA Fensome et al., 1993Class: DINOPHYCEAE Pascher, 1914Subclass: PERIDINIPHYCIDAE Fensome et al., 1993Order: GONYAULACALES Taylor, 1980Suborder: UNCERTAIN

Family: UNCERTAIN

Genus: HETEROSPHAERIDIUM Cookson and Eisenack, 1968Emendation: Yun (1981)Heterosphaeridium bellii sp. nov.2011 Heterosphaeridium heteracanthum (Deflandre and Cookson,1955) Eisenack and Kjellström, 1972 — Palamarczuk and Landman:148, pl. 5, fig. c.2012 Heterosphaeridium heteracanthum (Deflandre and Cookson,1955) Eisenack and Kjellström, 1972—Nøhr-Hansen: 70, pl. 6, fig. 2.Holotype: well 7120/7-3, sample 1370, England Finder referenceH39/4, Plate I, 1-3, 9.Paratype: well 7120/7-3, depth 1370 m, EF reference M41/1, Plate I,4, 5.Repository: PMO 224.498; lodged at the Paleontological Museum ofOslo, Norway.Type stratum and locality: Southwestern Barents Sea, well 7120/7-3,Torsk Fm., at 1370 m.

4.1.1. Stratigraphic rangeAccording to the authors' observation Heterosphaeridium bellii sp.

nov. occurs extensively throughout the Barents Sea (e.g. boreholes7119/12-1, 7120/5-1, 7121/5-1) and the Norwegian Sea (6707/10-1,6711/4-U-1). In addition, an increase in a comparable species calledHeterosphaeridium cf. H. heteracanthum or H. heteracanthum wasobserved in the Late Campanian Baculites compressus–Baculitescuneatus–Baculites reesidei ammonite zones in the Western InteriorBasin (Palamarczuk and Landman, 2011). The specimen ofH. heteracanthumprovidedbyPalamarczuk and Landman (2011) stronglyresemblesH. bellii sp. nov. and the interval characterised by its dominance(57% of the assemblage) is similar to that observed within the H. belliiacme from the Barents Sea. Thus, we assume that they are the samespecies.

In this study, the acme of Heterosphaeridium bellii sp. nov. occurstogether with Late Campanian species and above the LAO ofPalaeoglenodinium cretaceum, which according to Costa and Davey(1992) is characteristic of the Early Campanian age. The LSAO of H.bellii sp. nov. coincides with the LO of Raetiaedinium truncigerum in-dicating a Late Campanian age (Williams et al., 2004). The LCO of H.bellii sp. nov. has been recorded together with or just above the LO

Fig. 3. Selected palynological marker events identified in the Late Cretaceous sedimentary record in two analysed boreholes (Tromsø Basin).

32 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

of Odontochitina operculata and the LCO of Spongodinium delitiensesuggesting a Campanian to Maastrichtian age. An abundant occur-rence of S. delitiense was previously recorded in the Late Campanian

Fig. 4. Late Cretaceous and Palaeocene zonal schemes and palyno

by Nagy et al. (1997). The LO of O. operculata may indicate the EarlyMaastrichtian according to Costa and Davey (1992), Williams et al.(2004), Schiøler and Wilson (2001), and Antonescu et al. (2001).

logical events of the Barents Sea and other selected regions.

Table1

Distributionof

palyno

morph

sin

well7

119/9-1.

33W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

4.1.1.1. Etymology. Named in honour of David Graham Bell, an ex-pert on the Cretaceous palynology of the Norwegian ContinentalShelf.

4.1.1.2. Diagnosis. Gonyaulacacean, chorate cyst with an apicalarchaeopyle and non-tabular processes which have subequal length,but vary in shape. The processes may be solid or hollow. Their endingsare variable, but themajority have a characteristic “scythe-like” termina-tion with irregularly jagged ridges (Plate I, 9). The processes are neverconnected distally but may be connected proximally by very low crests.A paratabulation pattern has not been observed.

4.1.1.3. Description. The specimens possess an apical archaeopyle formedby the loss of presumably four antapical plates and only rarely detached,contiguous opercula were identified. Paratabulation is absent, reflectedonly by the archaeopyle that occasionally has a visible sulcal notch.Wall layers are adpressed and appear to be autophragm only.Wall orna-mentation displayed by the examined specimens varies from beingsmooth to finely punctate or striate. Numerous non-tabular processesof sub-equal length are characterised by differently-developed endings.The “scythe-like” terminations with jagged ridges (Plate I, 9) occur onthe majority of the processes. The remaining processes are usuallyopened distally. A single specimen of Heterosphaeridium bellii sp. nov.possesses both solid and hollow processes, which can also be hollow ba-sally and distally, but closed in the middle. The processes that nevershow a distal connection can be connected by very low crests that donot exceed 2 μm in height. The cyst body is often round to ovoidal,with an average diameter of 47 μm and the processes length 16 μm(twelve specimens measured). The holotype diameter equals 47.4 μmand the average process length is 15.2 μm (seven processes measured).The “scythe-like” endings are usually not wider than 5.2 μm.

4.1.1.4. Discussion. The newly described species Heterosphaeridium belliiis well-known in the hydrocarbon industry as Cleistosphaeridium sp. 1,Heterosphaeridium cf. heteracanthum or Heterosphaeridium sp. A. The dif-ferences between the genera Cleistosphaeridium and Heterosphaeridiumrelate to the nature of processes and their linkage. Davey et al. (1966,p. 166) described Cleistosphaeridium as an ovoidal, chorate cyst that is“typically closed distally and without communication to endocoel”.Similarly, Stover and Evitt (1978) stated in their diagnosis that the pro-cesses of Cleistosphaeridium have similar size and shape and are closeddistally. In contrast, Heterosphaeridium includes forms which possesstwo or three types of different processes in one specimen (Yun, 1981).The distal and proximal process linkage is a significant feature inHeterosphaeridium. The new species, H. bellii, possesses differenttypes of processes in one specimen and some of them are proximallylinked. They also possess different shapes of process endings whichoften are opened distally. Thus, H. bellii sp. nov. is assigned toHeterosphaeridium.

4.1.1.5. Comparison. Heterosphaeridium conjunctum has processes equalin length but more variable in width and narrowing towards thetips. Heterosphaeridium cordiforme has simpler and fewer processescovering a heart-shaped body. Heterosphaeridium spinaconjunctumand Heterosphaeridium verdieri have processes that are connecteddistally. Heterosphaeridium bellii sp. nov. differs significantly fromHeterosphaeridium difficile by lack of the conspicuously wide processesoccurring together with slimmer ones. Differences between H. bellii andHeterosphaeridium heteracanthum are provided below (see emendation).

Heterosphaeridium heteracanthum (Deflandre and Cookson, 1955)Eisenack and Kjellström, 1971, p. 451, emend. nov.1955 Hystrichosphaeridium heteracanthum (Deflandre and Cookson):276, pl. 2, figs. 5–6, text figs. 40–41.1965 Baltisphaeridium heteracanthum (Downie and Sarjeant): 91(not validly published).

Table2

Distributionof

palyno

morph

sin

well7

120/7-3.

34 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

Plate I. 1–9.Heterosphaeridium bellii sp. nov., southwestern Barents Sea: 1–3, 9. Holotype, well 7120/7-3, depth 1370 m, EF reference H39-4, PMO224.498; 4–5. Paratype, well 7120/7-3, depth1370 m, EF reference V40/1, PMO224.498; visible apical archaeopyle; 6.Well 7120/7-3, depth 1370 m, EF referenceM42/2, PMO224.498; 7.Well 7120/7-3, depth 1380 m, EF reference E55/1,PMO 224.499; 8. Well 7120/7-3, depth 1380 m, EF reference R54/4, PMO 224.499; 9. Typical “scythe-shaped” appendages; 10. Assemblage dominated by Heterosphaeridium bellii.

35W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

Fig. 5. Comparison of geophysical logs with palynological events.

36 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

1966 Cleistosphaeridium heteracanthum (Davey et al.): 168, pl. 2,figs. 6–7.1971 Heterosphaeridium heteracanthum (Eisenack and Kjellström):451, pl. 7, fig. 3.1978 Heterosphaeridium? heteracanthum (Stover and Evitt): 52.2004Heterosphaeridium heteracanthum (Fauconnier and Begouën inFauconnier and Masure): 269, pl. 35, figs. 7–8.

Original diagnosis of Deflandre and Cookson (1955 p. 276, asHystrichosphaeridium): Shell large, approximately circular in outline,with numerous appendages of variable shape, size and form. Appendagessolid, usually elongated, frequently filiform, sometimes as broad as long.The apices either pointed, everted or irregularly branched. Surface ofshale punctate. Dimensions: Shell 56–107 μm, appendages 5–36 μmlong (majority between 13 and 23 μm).

Emended diagnosis (based on original description and photograph ofDeflandre and Cookson, 1955, pl. 2, figs. 5, 6): Large, gonyaulacacean,circular in outline, chorate to proximo-chorate cyst with an apicalarchaeopyle. Numerous, non-tabular processes are characterised by vari-able shape, length and width. All processes are solid, usually elongatedand their endings differ significantly. They may be pointed, everted orirregularly branched, never “scythe-like” or distally connected. Wallstructure is punctate.

Comparison to Heterosphaeridium bellii: Heterosphaeridiumheteracanthum differs significantly from H. bellii sp. nov. by havingsolid processes of variable length and width, often strongly branchedand furcated at the ends and never “scythe-shaped” terminations. Theprocesses of H. bellii sp. nov. are rather constant in length and possessdifferent, “scythe-shaped” types of terminations. They are solid andhollow on one specimen. Some of the processes may be solid in themiddle and hollow at the ends. The endings are never branched as inH. heteracanthum. Additionally, crests observed in H. heteracanthumare much taller and more commonly observed than in H. bellii sp. nov.

Fig. 6.Palaeogeographicalmap of theArcticOcean and adjacent areas during the Turonian.The black spot indicates location of study area.Map modified after Jenkyns et al. (2004).

4.2. Palynological events

The succession of palynomorphs in both studied wells is described,based mainly on LO (last occurrence) events, and compared to pub-lished data from the Cretaceous of the North Sea (Costa and Davey,1992) and Greenland (Nøhr-Hansen, 1996, 2012) as well as from thePalaeogene in the Barents Sea (Nagy et al., 1997, 2004) and the NorthSea (Mudge and Bujak, 1996; Mangerud et al., 1999). Global dinoflagel-late cyst events described byWilliams et al. (2004) aswell as correlationto palynological assemblages from the ammonite-dated section in theWestern Interior Basin (Palamarczuk and Landman, 2011) have alsobeen used for comparison. Additionally, the observed LO events werecorrelated with mid-Norway data (Gradstein et al., 2010). Attempts to

compare the results with the dinoflagellate cysts events from Canada(Fensome et al., 2008a,b, 2009) revealed some interesting discrepan-cies. Relevant published zonal schemes are shown in Fig. 4. The presentdata comes from ditch cutting samples, and the events are thereforediscussedwith preference to last occurrences given the inherent problemof cavings.

4.2.1. PalaeoceneTheuppermost studied interval, overlying the LCOofHeterosphaeridium

bellii sp. nov., is characterised in bothwells by the LO of Cerodinium diebelii,the FO of Eisenackia margarita, the LO of Isabelidinium? viborgense,common Palaeocystodinium bulliforme, and the LAO Palaeoperidiniumpyrophorum (Fig. 3). The events correlate to the BSP 1: Psammosphaerafusca–Hyperammina rugosa zone of Palaeocene age described by Nagyet al. (2004) from the western Barents Sea (well 7119/9-1). Accordingto Gradstein et al. (2010), the LOs of I? viborgense and C. diebelii occur

37W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

in the Middle Palaeocene (Fig. 4). The LCO of P. bulliforme andabundant occurrences of P. pyrophorum are also well known from thePalaeogene in the North Sea (Mangerud et al., 1999). Species diagnosticfor the earliest Palaeocene and latest Maastrichtian have not beenrecorded.

4.2.2. Late Campanian to Early MaastrichtianThe LCO of Heterosphaeridium bellii sp. nov. was recorded at 1350 m

coincidingwith the LO of Odontochitina operculata in well 7120/7-3 andat 1450 m, 10 m above the LO of O. operculata in well 7119/9-1 (Fig. 3).According to Williams et al. (2004), Schiøler and Wilson (2001),Antonescu et al. (2001) andGradstein et al. (2010), the LOofO. operculataindicates an age no younger than the Early Maastrichtian. The LAO ofH. bellii sp. nov. has only been recorded in well 7119/9-1 (at 1460 m),where it co-occurs with the LO of O. operculata. Common Spongodiniumdelitiense are present in the same samples. Similar events indicating aLate Campanian to Early Maastrichtian age have been recorded in theBarents Sea by Nagy et al. (1997). The LSAO of H. bellii sp. nov. in well7120/7-3 has been recorded at 1370 m with an acme event from 1380 to1400 m. In the well 7119/9-1 the acme of H. bellii sp. nov. occurs at1490 m. The interval also comprises the LOs of Palaeohystrichophorainfusorioides, Raphidodinium fucatum and Trichodinium castanea. Fensomeet al. (2008a) and Williams et al. (2004) placed the LO of R. truncigerumin the Middle and Late Campanian. The LO of P. infusorioides suggests aCampanian age (Fensome et al., 2008a) or an Early Maastrichtian age(Gradstein et al., 2010). No species characteristic for the MiddleCampanian were recorded.

4.2.3. Early CampanianThe interval is characterised by a change in assemblage composition.

LOs of Chatangiella bondarenkoi, Chatangiella ditissima, Chatangiellagranulifera, Chatangiella manumii and LAOs of Circulodinium distinctumand Palaeoglenodinium cretaceum are recorded at 1410 m in well7120/7-3 (Fig. 3). Similar dinoflagellate cyst events are not recordedinwell 7119/-9-1, but that could be caused by thedensity of the samples

Fig. 7. Marine macrofossil zones for Campanian based on ammonoids of the Western Interiorshown abundant occurrence of Heterosphaeridium cf. heteracanthum and HeterosphaeridiumHeterosphaeridium bellii sp. nov.

available for this study (see Fig. 3). The LO of P. cretaceum andTrichodinium castanea recorded below (at 1420 m) suggest an age noyounger than Early Campanian (Costa and Davey, 1992). The LO ofCallaiosphaeridiumasymmetricum observedbelow inwell 7120/7-3 sug-gests an Early Campanian age (Costa and Davey, 1992; Fensome et al.,2009). Although the genusChatangiellamayoccur in the Late Campanian,Chatangiella bondarenkoi ismore typical of the Early Campanian (GrahamBell, personal communication 2010). Only one sample at 1570 m wasavailable from the corresponding interval in well 7119/-9-1 (Fig. 3), re-vealing no age diagnostic species.

4.2.4. Turonian to ConiacianA distinct down-hole change in dinoflagellate cyst composition

is observed also at 1440 m in well 7120/7-3 (Fig. 3). The LO ofHeterosphaeridium difficile suggests the Coniacian (Williams et al.,2004) or Santonian age (Costa and Davey, 1992; Prince et al., 1999;Fensome et al., 2008a, 2009). The LO of Chlamydophorella nyei indicatesConiacian, based on records from the Scotian Margin (Fensome et al.,2009) or Campanian (Prince et al., 1999). The LO of Dinopterygiumalatum may, according to Costa and Davey (1992), occur sporadicallyin the Santonian, but it is most consistently present in the Coniacianand older strata. The LCO of H. difficile at 1450 m is probably consistentwith the LAO of Gradstein et al. (2010) and indicative of the Turonian/Coniacian boundary. According to Gradstein et al. (2010), the LO ofS. coronatum is characteristic of the top of Turonian, which is in agree-ment with Costa and Davey (1992) from the North Sea. An increase ofSurculosphaeridium longifurcatum recorded above (at 1470 m) may becompared to the LAO of S. cf. longifurcatum, which, according toGradstein et al. (2010) also indicates the Turonian, supporting Turonianto Coniacian age for this interval (Fig. 3).

4.3. Discussion

The Kveite Formation is generally regarded as of Late Cenomanian toEarly Maastrichtian age (Worsley et al., 1988). However, only Turonian

of USA and inoceramids of North America and Europe (after Ogg and Hinnov, 2012). Theheteracanthum (Palamarczuk and Landman, 2011) is considered to be equivalent of

Fig. 8. Published ranges of selected dinoflagellate cysts from different regions.

38 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

to Coniacian, Early Campanian and Late Campanian to EarlyMaastrichtianintervals have been recorded in the investigated sections of Kveite Forma-tion. The top of the formation in studied boreholes is regarded as LowerMaastrichtian. The Cretaceous/Palaeogene contact in well 7120/7-3should be re-considered to be placed lower, as indicated by the record-ed last occurrences of some Palaeocene dinocyst events. Such a conclu-sion is supported by the petrophysical logs including a decrease in logdensity at 1450 m in well 7119/9-1, which correlates with 1350 m inwell 7120/7-3 (Fig. 5).

Concerning calibration of Upper Cretaceous strata, Birkelund (1965)first noticed that the Campanian ammonite species from Europe arecomparable with those from the Western Interior of North America.She suggested that Campanian scaphites and baculites migrated fromthe Western Interior Basin, resulting in an arrival in Europe by LateCampanian time. A detailed Late Cretaceous (Cenomanian toMaastrichtian) ammonite zonation from the North America WesternInterior was standardized by Cobban (1993) and Cobban et al.(2006). Ogg and Hinnov (2012) demonstrated the co-occurrence ofsimilar inoceramid taxa in North America and Europe. Comparisonof Maastrichtian macrofossils and palynostratigraphic results fromWest and southern East Greenland to the ammonite zones from theWestern Interior Basin also shows good calibration (Nøhr-Hansen,1996, 2012). In addition, the dinoflagellate cyst events documentedin the Western Interior Basin from the Baculites compressus–B.cuneatus–B. reesidei zones (Palamarczuk and Landman, 2011) aresimilar to those recorded in the studied samples and assigned toUpper Campanian. According to the ammonite zonation of theWesternInterior of North America published in Ogg and Hinnov (2012), theyrepresent the Upper Campanian.

This study yielded a record of dinoflagellate cysts comparable tothose described by Nøhr-Hansen (1996, 2012) as well as Palamarczukand Landman (2011). As shown by Jenkyns et al. (2004) the Arctic

Ocean was, as early as during the Turonian, most likely connected tothe epicontinental seas (Fig. 6). Our hypothesis is therefore, that theacme of H. bellii sp. nov. in the southwestern Barents Sea correlates tothe interval from the Western Interior Basin. The abundance ofHeterosphaeridium cf. H. heteracanthum and H. heteracanthum recordedwithin the Late Campanian Baculites compressus–B. cuneatus–B. reesideiammonite zones is in this study described asHeterosphaeridium bellii sp.nov. acme. It enables a calibration of our dinocyst record to the LateCampanian from the Western Interior, suggesting that the H. bellii sp.nov. is an important biostratigraphical marker.

Regional correlations showgreat similarities not onlywith dinoflagel-late cysts recorded in Greenland (Nøhr-Hansen, 1996, 2012), the BarentsSea (Nagy et al., 1997, 2004), and theWestern Interior (Palamarczuk andLandman, 2011), but also with mid-Norway (Gradstein et al., 2010),offshore Norway (Costa and Davey, 1992) and NML — NorthernHemisphaere mid-latitudes (Williams et al., 2004).

The correlation is partly inconsistent with the palynologicaldata from Canada (Fensome et al., 2009), particularly regarding the re-ported ranges of Heterosphaeridium difficile, Stephodinium coronatum,Surculosphaeridium longifurcatum and Trichodinium castanea (Fig. 8). TheLO of H. difficile may indicate Coniacian (Williams et al., 2004) orSantonian (Costa and Davey, 1992; Prince et al., 1999; Fensome et al.,2008a, 2009). The LO of S. coronatum is considered to be a marker forthe top of the Turonian (Costa and Davey, 1992; Gradstein et al., 2010).The Coniacian age of S. coronatum described by Williams et al. (2004) isunreliable as it is based on specimens known to be misidentified (MartinPearce, personal communication, 2013). The LO of S. longifurcatum ac-cording toCosta andDavey (1992) is of Early Santonian age and accordingto Fensome et al. (2009) of Middle Campanian age (Fig. 7). The LO ofT. castanea according to Costa and Davey (1992) indicates the EarlyCampanian but it may also represent the Late Campanian (Fensomeet al., 2009) or the EarlyMaastrichtian (Williamset al., 2004). Generally,

39W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

the selected Last Occurrences of species recorded in Canada (Fensomeet al., 2009) as well as those described byWilliams et al. (2004) suggestyounger ages. The dinoflagellate cysts recorded in this study differfrom those present in the Turonian to Santonian of Northern Siberia(Lebedeva, 2006) in the low number of comparable dinocyst species,which suggests either taxonomical discrepancy or limited marineconnection between the regions.

5. Conclusion

Based on palynological analysis from cutting material from theKveite and Torsk formations in two exploration wells in the BarentsSea area, distinct dinoflagellate cyst events ranging in age from theTuronian to Palaeocene have been revealed. The study documents thepresence of minor hiatuses within the southwestern Barents Sea suc-cession: the Upper Cenomanian, Santonian, Middle Campanian andUpper Maastrichtian to Lower Palaeocene seem to be missing there(Radmacher, personal observations).

The investigated interval compares well with assemblages recordedin Greenland (Nøhr-Hansen, 1996, 2012), and the palynological eventsseem to have a regional distribution with biostratigraphic and correla-tion potential.

Heterosphaeridium bellii sp. nov. has been described, with an acmecharacteristic for the Late Campanian. A species identical to H. bellii sp.nov., called Heterosphaeridium cf. H. heteracanthum or Heterosphaeridiumheteracanthum, occurs with an acme event in ammonitedated beds inthe Western Interior Basin (Palamarczuk and Landman, 2011).Heterosphaeridium heteracanthum emend. nov. differs significantly fromH. belli sp. nov.

Acknowledgements

The authorswould like to thank theNorwegian PetroleumDirectoratefor the loan of palynological slides and Statoil for providing samples. Weare grateful for the help of Henk Brinkhuis, Jan van Tongeren and NatasjaWelters from the Laboratory of Palaeobotany and Palynology in Utrecht,where some of the samples were processed. We are also grateful to thefollowing people for their help in various stages of the project: GrahamBell, Martin Pearce, Mike Kaminski, Przemysław Gedl, Eiichi Setoyamaand Stijn de Schepper. WR was co-financed by technical assistancefunds of the EEA Financial Mechanism and the Norwegian FinancialMechanism within the framework of the Scholarship and Training Fund.JT was supported by the ING PAN internal “MIKRO” project. The authorsacknowledge the reviewers for their detailed and helpful comments onthe manuscript.

References

Antonescu, E., Foucher, J.C., Odin, G.S., Schiøler, P., Siegl-Farkas, A., Wilson, G.J., 2001.Dinoflagellate cysts in the Campanian–Maastrichtian succession of Tercis Les Bains(Landes, France), a synthesis. In: Odin, G.S. (Ed.), The Campanian-MaastrichtianBoundary. Elsevier Science, Paris, pp. 253–264.

Birkelund, T., 1965. Ammonites from the Upper Cretaceous of West Greenland. Bull.Grønl. Geol. Unders. 56, 1–192.

Birkenmajer, K., 1981. The geology of Svalbard, the western part of the Barents Sea andthe continental margin of Scandinavia. In: Narin, A.E.M., Churkin, M., Stehli, F.G.(Eds.), The Oceans Basins and Margins. The Arctic Ocean, 5. Plenum Press, NewYork, pp. 265–329.

Bütschli, O., 1885. Erster band. Protozoa. In: Bronn, H.G. (Ed.), Klassen und Ordnungen desThier-Reichs, wissenschaftlich dargestellt in Wort und Bild. C. F. Winter'scheVerlagsbuchhandlung, Leipzig and Heidelberg, pp. 865–1088.

Cobban, W.A., 1993. Diversity and distribution of Late Cretaceous ammonites, WesternInterior, United States. In: Caldwell, W.G.E., Kauffman, E.G. (Eds.), Evolution of theWestern Interior Basin. Geological Associacion of Canada, pp. 435–451 (Special Paper).

Cobban, W.A., Walaszczyk, I., Obradovich, J.D., McKinney, K.C., 2006. A USGS zonaltable for the Upper Cretaceous Middle Cenomanian-Maastrichtian of the western in-terior of the United States based on Ammonites, Inoceramids, and Radiometric Ages.U. S. Geological Survey Open-File Report 2006-1250, p. 45.

Cookson, I.C., Eisenack, A., 1968. Microplankton from two samples from Gingin Brook No.4 Borehole, Western Australia. J. R. Soc. West. Aust. 51, 110–122.

Costa, L.I., Davey, R.J., 1992. Dinoflagellate cysts of the Cretaceous System. In: Powell, A.J.(Ed.), A Stratigraphic Index of Dinoflagellate Cysts. British MicropalaeontologicalSociety Publication Series; Chapman and Hall, London, pp. 99–153.

Dallmann,W.K., 1999. Lithostratigraphic Lexicon of Svalbard. Upper Palaeozoic to Quater-nary bedrock. Review and recommendations for nomenclature use. Committee onthe Stratigraphy of Svalbard.Norsk Polarinstitutt, Tromsø (320 pp.).

Davey, R.J., Downie, C., Sarjeant, W.A.S., Williams, G.L., 1966. Fossil dinoflagellate cysts at-tributed to Baltisphaeridium. In: Davey, J.R., Downie, C., Sarjeant, W.A.S., Williams, G.L.(Eds.), Studies on Mesozoic and Cainozoic Dinoflagellate Cysts. Bulletin of the BritishMuseum (Natural History), Geology, London, pp. 1–248.

Deflandre, G., Cookson, I.C., 1955. Fossil microplankton from Australian LateMesozoic andTertiary sediments. Aust. J. Mar. Freshwat. Res. 6, 242–313.

Doré, A.G., 1991. The structural foundation and evolution of the Mesozoic seaways be-tween Europe and the Arctic. Palaeogeogr. Palaeoclimatol. Palaeoecol. 87, 441–492.

Downie, C., Sarjeant, W.A.S., 1965. Bibliography and index of fossil dinoflagellates andacritarchs. Geological Society of America, Memoir 94, 1-180

Eisenack, A., Kjellström, G., 1971. Katalog der Fossilen Dinoflagellaten, Hystrichosphärenund Verwandten Mikrofossilien. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart(1132 pp.).

Eisenack, A., Kjellström, G., 1972. Katalog der Fossilen Dinoflagellaten, Hystrichosphären undVerwandten Mikrofossilien. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart.

Faleide, J.I., Vågnes, E., Gudlaughsson, S.T., 1993. Late Mesozoic–Cenozoic evolution of thesouth-western Barents Sea in a regional rift-shear tectonic setting. Mar. Pet. Geol. 10,186–214.

Fauconnier, D., Masure, E., 2004. Les dinoflagellés fossiles. Guide pratique de détermination.Les genres à processus et à archéopyle apical.BRGM Editions, Orléan.

Fensome, R.A., Taylor, F.J.R., Morris, G., Sarjeant, W.A.S., Wharton, D.I., Williams, G.L., 1993.A classification of living and fossil dinoflagellates. Micropaleontology Press SpecialPaper 7. (351 pp.).

Fensome, R.A., Crux, J.A., Gard, I.G., MacRae, R.A., Williams, G.L., Thomas, F.C., Fiorini, F.,Wach, G., 2008a. The last 100 million years on the Scotian Margin, offshore easternCanada: an event-stratigraphic scheme emphasizing biostratigraphic data. Atl. Geol.44, 93–126.

Fensome, R.A., MacRae, R.A., Williams, G.L., 2008b. DINOFLAJ2, Version 1, American Asso-ciation of Stratigraphic Palynologists. http://dinoflaj.smu.ca/wiki/Main_Page.

Fensome, R.A., Williams, G.L., MacRae, R.A., 2009. Late Cretaceous and Cenozoic fossildinoflagellates and other palynomorphs from the Scotian Margin, offshore EasternCanada. J. Syst. Palaeontol. 7, 1–79.

Gradstein, F.M., Kaminski, M.A., Agterberg, F.P., 1999. Biostratigraphy and paleoceanographyof the Cretaceous seaway between Norway and Greenland. Earth Sci. Rev. 46, 27–98.

Gradstein, F.M., Anthonissen, E., Brunstad, E., Charnock, M., Hammer, O., Hellem, T., Lervik,K.S., 2010. Norwegian Offshore Stratigraphic Lexicon (NORLEX). Newsl. Stratigr. 44,73–86.

Gradstein, F.M., Ogg, J.G., Schmitz,M.D., Ogg, G.M., 2012. TheGeologic Time Scale 2012, v. 2.Elsevier Science, Oxford.

Jenkyns, H.C., Forster, A., Schouten, S., Sinninghe Damsté, J., 2004. High temperatures inthe Late Cretaceous Arctic Ocean. Nature 432, 888–892.

Kaminski, M.A., Setoyama, E., Tyszka, J., 2009. Plectoeratidus subarcticus, n.gen., n.sp., anew agglutinated foraminifer from the Upper Cretaceous of the western BarentsSea. Ann. Soc. Geol. Pol. 79, 141–146.

Kelly, S.R.A., 1988. Jurassic through Cretaceous stratigraphy of the Barents shelf. In:Harland, W.B., Dowdeswell, E.K. (Eds.), Geological Evolution of the Barents ShelfRegion. Graham and Trotman, London, pp. 109–130.

Lebedeva, N.K., 2006.Dinocyst biostratigraphy of theUpper Cretaceous ofNorthern Siberia.Paleontol. J. 40, S604–S621.

Mangerud, G., Dreyer, T., Søyseth, L., Martinsen, O., Ryseth, A., 1999. High resolution bio-stratigraphy and sequence development of the Palaeocene succession, Grane Field,Norway. In: Underhill, J.R. (Ed.), Development and Evolution of the Wessex Basin.Geological Society Special Publications, London, pp. 167–184.

Mudge, D.C., Bujak, J.P., 1996. An integrated stratigraphy for the Paleocene and Eocene ofthe North Sea. In: Knox, R.W.O. (Ed.), Correlation of the Early Paleogene in NorthwestEurope. Geological Society Special Publication, pp. 91–113.

Nagy, J., Kaminski, M.A., Johnsen, K., Mitlehner, A.G., 1997. Foraminiferal, palynomorph,anddiatombiostratigraphy andpaleoenvironments of theTorsk Formation:A referencesection for the Paleocene–Eocene transition in the western Barents Sea. In: Hass, H.C.,Kaminski, M.A. (Eds.), Contributions to the Micropaleontology and Paleoceanographyof the Northern North Atlantic. Grzybowski Foundation, Kraków, pp. 15–38.

Nagy, J., Kaminski, M.A., Gradstein, F.M., Johnson, K., 2004. Quantitative foraminiferal andpalynomorph biostratigraphy of the Paleogene in the southwestern Barents Sea. In:Bubίk, M., Kaminski, M.A. (Eds.), Proceedings of the Sixth International Workshopon Agglutinated Foraminifera. Grzybowski Foundation, Kraków, pp. 359–380.

Nøhr-Hansen, H., 1993a. Dinoflagellate cyst stratigraphy of the Barremian to Albian,Lower Cretaceous, North-East Greenland. Bull. Grønl. Geol. Unders. 166, 1–171.

Nøhr-Hansen, H., 1993b. Upper Maestrichtian?—Lower Paleocene dinoflagellate cysts andpollen from Turbidites in the Itilli Region, Nuussuaq, Central West Greenland. Firstdating of sediments. Bull. Grønl. Geol. Unders. 159, 81–87 (Repport).

Nøhr-Hansen, H., 1994. Dinoflagellate cyst biostratigraphy of the Upper Cretaceous BlackMudstones on SvartenhukHalvo,westernGreenland. Bull. Grønl. Geol. Unders. 94, 1–25.

Nøhr-Hansen, H., 1996. Upper Cretaceous dinoflagetllate cyst stratigraphy, onshoreWestGreenland. Bull. Grønl. Geol. Unders. 170, 1–104.

Nøhr-Hansen, H., 2012. Palynostratigraphy of the Cretaceous–lower Palaeogene sedimen-tary succession in the Kangerlussuaq Basin, southern East Greenland. Rev. Palaeobot.Palynol. 178, 59–90.

Nøhr-Hansen, H., Dam, G., 1997. Palynology and sedimentology across a new marineCretaceous–Tertiary boundary section on Nuussuaq, West Greenland. Geology25, 851–854.

40 W. Radmacher et al. / Review of Palaeobotany and Palynology 201 (2014) 29–40

Ogg, J.G., Hinnov, L.A., 2012. Cretaceous. In: Gradstein, F., Ogg, J.G., Schmitz, M.D., Ogg,G.M. (Eds.), The Geologic Time Scale 2012. Elsevier Science, Oxford, pp. 793–854.

Palamarczuk, S., Landman, N.H., 2011. Dinoflagellate cysts from the upper Campanian PierreShale and Bearpaw Shale of the U.S. Western Interior. Rocky Mt Geol. 46, 137–164.

Pascher, A., 1914. Über Flagellaten und Algen. Ber. Deut. Bot. Ges. 32, 136–160.Prince, I.M., Jarvis, I., Tocher, B.A., 1999. High-resolution dinoflagellate cyst biostratigra-

phy of the Santonian-basal Campanian (Upper Cretaceous): New data fromWhitecliff, Isle of Wight, England. Rev. Palaeobot. Palynol. 105, 143–169.

Ren, S., Faleide, J.I., Skogseid, J., Gradstein, F., 2003. Late Cretaceous–Paleocene tectonicdevelopment of the NW Vøring Basin. Mar. Pet. Geol. 20, 177–206.

Schiøler, P., Wilson, G.J., 2001. Dinoflagellate biostratigraphy around the Campanian–Maastrichtian boundary at Tercis Les Basins, southwest France. In: Odin, G.S. (Ed.),The Campanian–Maastrichtian boundary. Elsevier Science, Paris, pp. 221–234.

Setoyama, E., Kaminski, M.A., Tyszka, J., 2011a. Late Cretaceous agglutinated foraminiferaand implications for the biostratigraphy and palaeobiogeography of the southwest-ern Barents Sea. In: Kaminski, M.A., Filipescu, S. (Eds.), Proceedings of the Eighth In-ternational Workshop on Agglutinated Foraminifera. The Grzybowski Foundation,Cluj-Napoca, pp. 251–309.

Setoyama, E., Kaminski, M.A., Tyszka, J., 2011b. A study of Campanian agglutinated fora-minifera from the Lomonosov Ridge, IODP Leg 302, ACEX, in the paleogeographiccontext of the Arctic. Micropaleontology 57, 507–530.

Setoyama, E., Kaminski, M.A., Tyszka, J., 2011c. The Late Cretaceous–Early Paleocenepalaeobathymetric trends in the southwestern Barents Sea — Palaeoenvironmentalimplications. Palaeogeogr. Palaeoclimatol. Palaeoecol. 307, 44–58.

Setoyama, E., Radmacher, W., Kaminski, M.A., Tyszka, J., 2013. Foraminiferal andpalynological biostratigraphy and biofacies from a Santonian–Campaniansubmarine fan system in the Vøring Basin (offshore Norway). Mar. Pet. Geol.43, 396–408.

Stover, L.E., Evitt, W.R., 1978. Analyses of Pre-Pleistocene organic-walled Dinoflagellates.Stanford University Publications, California.

Taylor, F.J.R., 1980. On dinoflagellate evolution. BioSystems 13, 65–108.Williams, G.L., Brinkhuis, H., Pearce, M.A., Fensome, R.A., Weegink, J.W., 2004. Southern

ocean and global dinoflagellate cyst events compared: index events for the LateCretaceous–Neogene. In: Exon, N.F., Kennett, J.P., Malone, M.J. (Eds.), Proceedingsof the Ocean Drilling Program, scientific results, 189. Ocean Drilling Program,Texas, pp. 1–98.

Williams, G., Payne, S.N.J., Dyer, R., Ewen, D., Patrick, N., Watson, P., 2005. Non-acidwellsite palynology: widening opportunities. In: Powell, A.J., Riding, J.B. (Eds.), RecentDevelopment in Applied Biostratigraphy. The Micropalaeontological Society, SpecialPublications, London, pp. 219–235.

Worsley, D., 2008. The post-Caledonian development of Svalbar`d and the western Ba-rents Sea. Polar Res. 27, 298–317.

Worsley, D., Johansen, R., Kristiansen, S.E., 1988. TheMesozoic and Cenozoic succession ofTromsøflaket. In: Dalland, A., Worsley, D., Ofstad, K. (Eds.), A lithostratigraphicscheme for the Mesozoic and Cenozoic succession offshore mid- and northernNorway. Norwegian Petroleum Directorate, Stavanger, pp. 42–65.

Yun, H., 1981. Dinoflagellaten aus der Oberkreide (Santon) von Westfalen. Palaeontogr.Abt. B 177, 1–89.