BASTERIA,71:157-168,2007 Notes onthe systematics, morphology andbiostratigraphy of fossil holoplanktonic Mollusca, 19. Pteropods (Gastropoda, Euthecosomata)fromtheEocene Lillebaelt Clay Formation(Denmark, Jylland) Arie+W. Janssen Nationaal Natuurhistorisch MuseumNaturalis (PalaeontologyDepartment),P.O.Box 9517,NL2300RA Leiden,The Netherlands;currently: 12,Triqtal'Hamrija,XewkijaXWK9033,Gozo, Malta; [email protected] Kai+Ingemann Schnetler Fuglebakken 14,Stevnstrup, DK 8870Langa,Denmark; [email protected] & Claus Heilmann-Clausen DepartmentofEarthSciences,Aarhus University,DK 8000ArhusC.,Denmark; [email protected]. Sideriticfossiliferous concretions fromtheEoceneLillebaelt Clay Formation,collected exsitu onthe beach atTrelde Næs (Jutland,Denmark) were found to yieldtwo commonpteropod species:Heliconoides lillebaeltensis spec. nov.and H.mercinensis (Watelet&Lefèvre,1885),thelat- terknown to date from aLatePalaeocene-Ypresianinterval. Asinglefurtherspecimen might representthe speciesLimacinapygmaea (Lamarck,1805),knownonlyfromtheLutetian.Astudy ofthe dinoflagellateassemblagesin six ofthe concretions allowed anageassignmentofEarly Lutetian. Key words: Gastropoda, Euthecosomata,Heliconoides,Limacina, taxonomy, dinoflagellates, biostratigraphy, Eocene,Lutetian,Denmark. INTRODUCTION (K.I. Schnetler) AtTreldeNaespeninsula, NorthofFredericia(Jutland, Denmark), Eocenefossilbear- ing sideriticconcretionsand pyritic mouldsof fossils are found onthebeaches,washed outof clays cropping outincoastalcliffs. Inpractically allconcretions molluscsarepoor- ly preserved, as the original aragonitic shell materialis dissolved, leaving internal and externalmoulds allowing casting with silicone latex. Quite a numberof them yielded pteropods, amongwhichis anundescribedspecies. Materialhasbeencollectedsince the1960s(Bonde, 1968).Astudy ofthebenthicmol- luscsisforthcoming (Schnetler& Heilmann-Clausen,inprep.). Sincethe1990smanycon- cretionscontaining limacinidpteropod species werecollectedbytwo Danishprivate col- lectors, whicharedescribedhere. The following abbreviations are used:BMNH, The Natural History Museum, London, England; OB, colln O. BarsoeHansen, Kolding, Denmark; ISL, collnK.I. Schnetler, Langa, 1Fornr 18inthisseries seeBasteria70: 85. 158 BASTERIA,Vol 71, No.4-6,2007 Denmark;MGUH, GeologicalMuseum,Copenhagen, Denmark;MM, collnMogens Madsen, Fredericia, Denmark; RGM, Nationaal Natuurhistorisch Museum Naturalis (Palaeontology Department) (formerly Rijksmuseum vanGeologie enMineralogie), Leiden,TheNetherlands. LOCALITY (K.I. Schnetler) (fig. 1) The fossil bearing concretions originate from thesouthern coast of theTrelde Naes peninsula (fig. 1). Eocene sediments are present, underlying Quaternary deposits, throughout the country in NW-SE direction, connectedwith deposits ofthesame agein northernGermany (fig. 1).The deposits are theRosnaesClay, LillebseltClay and Sovind Marlformations, allof Eoceneage. Previously also Late Oligocene sediments(Brejning Clay, Vejle Fjord Formation) were cropping out in the southern part of the cliff, near Kirstinebjerg Skov (Schnetler, 1985). The occurrence is now considered glacially trans- ported. As theconcretionsgenerally arefoundexsitu onthebeach,itis difficulttoreferthem tooneparticularbed.Collins&Jakobsen(2003)thus consideredadecapod faunafromthe concretionstobe ofYpresian/Lutetian age.Inanumberof concretionsHeliconoidesspeci- menswere foundco-occurring withdecapods (Mogens Madsen, pers. comm.,2007,and observationsbythesecondauthor). Theconcretions withHeliconoidesspecies, asspecified inthesystematic partbelow, containedinonly twocases othermolluscs(Volutocorbis spec, and Cuspidaria spec.) and furthermore, the two Heliconoides species have been found togetherinjust afew cases. Thepalaeodepth wasestimatedtobeover 200m (Heilmann- Clausen, 1995). Fig. 1.Mapshowingthe distribution oftheEocene deposits(inblack), withlocation map ofTreldeNæs (afterGravesen, 1993,and Collins&Jakobsen,2003). Janssen etal.: Pteropodsfromthe EoceneLillebaeltClay Formation(Denmark, Jylland) 159 STRATIGRAPHY (C. Heilmann-Clausen) (fig.2) Provenanceoftheconcretions.- Thecliffsexpose glaciallydisturbedbedsfrommost of the Eocene LillebaeltClayFormation, i.e., the Beds L2-L6 (Heilmann-Clausen et al., 1985)(fig.2).On theopposite coastof TreldeNaesthelowerpartoftheoverlying Eocene Fig. 2. Compositestratigraphic section ofLillebælt ClayFormation (right-handcolumn)atTrelde Næs (afterHeilmann-Clausen etal., 1985, andMichelsen etal., 1998). 160 BASTERIA,Vol. 71, No. 4-6,2007 Sovind Marl Formationis exposed. The stratain thecliffsof TreldeNaesare veryrich in dinoflagellate cysts, originally described in an unpublished master's thesis (Heilmann- Clausen, 1978). Asubsequent study of the entireDanish Eocene led to a dinoflagellate zonation, partially with a first order calibrationto the calcareous nannofossil zonation (Heilmann-Clausen, 1988). Finally, a detailed stratigraphic-systematic study of the dinoflagellate succession in acoredsectionoftheLutetian-basalRupelian of Denmarkis provided by Heilmann-Clausen& van Simaeys (2005). Forthe present study dinoflagellate cysts havebeen examinedfromc. 12 gsamples of two concretions, OB 1203with Heliconoideslillebaeltensisspec. nov. and OB 689 with Heliconoidesmercinensis.Thecarbonateoftheconcretions was dissolvedwithcold5NHC1 and after dilutionwith water theresidues were sieved on20 micron nylon filters. The sievedresidues mainly consistofdinoflagellate cystsandwere mountedinglycerine-jelly on slides for light-microscopy. Several thousandwell preserved cysts were recovered fromeachsample. SampleOB 1203containsarathertypical assemblage oftheWetzeliellaarticulata-ovalis Zoneof Heilmann-Clausen(1988), with 7%Cleistosphaeridium diversispinosum (formerly identifiedas Systematophoraplacacantha, seeHeilmann-Clausen& vanSimaeys,2005), and 6% Areosphaeridium diktyoplokum-michoudii group.Wetzeliellaarticulata-ovalisisalso com- mon (4%). Dracodinium samlandicum and Hystrichosphaeropsis costae (= H. cf. ovum of Heilmann-Clausen, 1988)were notobserved, probably excluding thelower partof the Czone, wlheich isiaslso stupoportesd bypthehmodearateeabunrdanicdeof ium diver- sispinosum. The assemblage clearly points to Bed L5 of the LillebaeltClay Formation (Heilmann-Clausen, 1988). Sample OB689contains anassemblage generally similartothat ofsample OB 1203, eWxceptfor thepreesenceofWtilsonzidiumecheinosuturaltumaindetheabsencle olf aarti- culata-ovalis. Cleistosphaeridium diversispinosum accounts for 9% of the assemblage. The aEbsence ofamarkers tofoloder and ynounger zionecs (Dracoydinium psachydermtum,a ursulaeandPhthanoperidinium regalis)clearly refers thisassemblage to theWetzeliellaarti- culata-ovalis Zone. W. echinosuturatumhas previously been recorded in the overlying P. regalis Zone (new name for the P. geminatum Zone of Heilmann-Clausen, 1988, see Heilmann-Clausen& van Simaeys, 2005) and may well occur sporadically in theupper part ofthe W.articulata-ovalis Zoneas well. The sample probably originates froma level abovesample OB 1203,andmaylithostratigraphically be derivedfromBed L5, or possi- bly BedL6,oftheLillebaeltClay Formation. Age of the concretions, based on dinoflagellate assemblages. - The base of the Phthanoperidinium regalis Zone in Denmarkis probably nearthe baseof the NP15 Zone, although previous nannofossil identifications correlated this level with NP14, see Heilmann-Clausen& van Simaeys (2005: 194). TheWetzeliellaarticulata-ovalis Zonewith thetwo concretionscan be correlatedwiththeupperpartof NP14 or lowermostpart of NP15. TheYpresian-Lutetian boundary, as currently used, is inlower NP14, ata clearly olderlevelthantheWetzeliellaarticulata-ovalisZone. In conclusion, theconcretions canbe referredtotheEarly Lutetian,as currently defined(Luterbacher etal., 2004). Note added in proof. - Four additional concretions with Heliconoides have been analysed for dinoflagellates; oneconcretion(2001/57) includedbothH. lillebaeltensisand H. mercinensis, andthree concretions(2001/59, OB 932and OB982) containedH. merci- nensis.The dinoflagellate assemblages are similartothoseinthealready studiedconcre- tions andcomparetothehigherpart ofthe W. articulata-ovalisZone. The concretions are thereforemost probably washed outofBedL5(one of them,OB 982withW. echinosutu- ratum,mightcomefrom BedL6). Janssenetah: Pteropodsfrom theEoceneLillebaeltClay Formation(Denmark, Jylland) 161 The additional concretions corroboratethe upper Lillebaelt Clay provenance and Early LutetianageoftheentirestudiedmaterialfromTreldeNaes. SYSTEMATICPART (A.W.Janssen) Theconcretionscontaining(among otherspecimens) theholotypeand theillustrated specimens, as wellasalmost allconcretions collectedby MM arehoused inMGUH, five concretions(leg./don. MM), are in colln ISL, oneconcretion(leg./don. MM) is in colln RGM, allotherconcretionsare intheOB private collection.Siliconecasts ofallspecimens referredto are furthermorein collnISL andRGM. Family LimacinidaeGray, 1847 Heliconoidesd’Orbigny, 1836 Type species - Heliconoides inflata (d'Orbigny, 1836),by subsequent designation(Herrmannsen, 1846) (Recent). Heliconoideslillebaeltensisspec. nov. (figs 3-8, 12-13) Holotype. - Figs 3and 13, external mouldofspecimen insideritic concretionnrOB 229, leg. O.BarsoeHansen (Kolding, Denmark),2004,collnMGUH 28735;silicone latex casts in collnISLand RGM541.508.Thesame concretion contains 13 furtherspecimens (paratypes), threeofwhichillustrated(figs 4-6). Locus typicus. - TreldeNaes, NorthofFredericia,Jylland, Denmark, collectedex situ onforeshore. Stratum typicum.- LillebaeltClay Formation(Eocene). Derivatio nominis. - Thespecies is namedafter theLillebaeltsound, whichgave its nametotheLillebaeltClayFormation,fromwhichthepresentmaterialoriginates. Description. - Shellsmall (holotype: H2.1 mm,W 2.2 mm), sinistral, rounded coni- cal, slightly widerthanhighto slightly higherthan wide,withabout5whorls, attaching above theperiphery oftheforegoingwhorl.Thewhorlsincrease slowly and gradually in diameter.Thebody whorloccupies c.90%ofthetotalshellheight.Thebaseoftheshellis rounded,umbilicated;umbilicusapproximately onefifthofbody whorldiameter(fig.4). Theapertureis obliquely droplet-shaped, pointed aboveandroundedbelow, higherthan wide, its height c. threequartersof the total shell height. The apertural margin is rein- forcedexternally (not visibleintheholotype, butobservedinseveral paratypes,figs 2,3, 5, 6)by anarrow ridge or margin-parallel foldthatinsomespecimens seems tobeslight- ly sigmoid. Columellainvisiblein allavailablespecimens. Variability seemstoberestrict- ed toaslightly higheror lowerspira. Paratypes. - Allspecimens fromthetypelocality: fourconcretions with11specimens, leg. M. Madsen,2000-2006, collnMGUH, siliconecasts in ISL2007.1-3,2007.5,and RGM 541.501-503,RGM541.505. Four concretions withseven specimens, leg. M.Madsen, 1999, ISL1999.56-57and 1999.60-61,silicone castsin ISLand RGM 429.552-553,RGM429.555- 556. One concretionwithten specimens, leg. M.Madsen, 2006 (MM 2006/18), don.2007, RGM541.507(this specimens also contains c. 55 specimens of Heliconoidesmercinensis). Siliconecast in collnISL2007.7.One concretionwiththe holotype and 13 furtherspeci- 162 BASTERIA,Vol. 71, No.4-6, 2007 Figs 3-11.Heliconoides and Limacina spp. 3-8,Heliconoides lillebaeltensis sp. nov., silicone latex castsof3, holotypeand 4-6, paratypes, all in concretion OB 229 (compare figs 12-13),RGM541.508,originalin MGUH 28735;7,paratype,silicone latexcast ofspecimeninOB881,RGM541.515,originalinMGUH 28736;8,paratype,silicone latexcast ofspecimeninOB 1065,RGM541.518,originalinMGUH28737,all leg./don.OleBarsøe Hansen; 9-10, Heliconoides mercinensis (Watelet&Lefèvre, 1885),9,BMNHGG7117, leg.D.Curry; 10,silicone latexcast ofspecimen inOB868,RGM541.514,original inMGUH 28738;11, Limacina pygmaea(Lamarck, 1805)?,silicone latex castofspecimeninOB 1072,RGM541.519,originalin MGUH 28739, leg./don. Ole Barsøe Hansen. Figs 3-8 and 10-11 from Trelde Næs (Jutland, Denmark; Lillebaelt Formation,EarlyLutetian),fig.9fromAizy-Jouy (Aisne,France;Sables de Cuise,Ypresian). mens, leg. O.BarsoeHansen,2004(OB229, collnMGUH 28735), threeconcretions withc. 55 specimens (OB 577,675, 851)(holotype and threespecimens in OB 229 illustratedfigs 3-6); silicone castsin ISL 2007.8-9,2007.11,2007.13and RGM541.508-509,RGM541.511, RGM 541.513).Fourconcretions, with33specimens, leg./don.O. BarsoeHansen,2007(OB 868,OB881,OB 1065,OB 1072),collnMGUH (onespecimen inOB881 andoneinOB1065 illustratedfigs 7-8,MGUH28736-28737);silicone casts inISL2007.14-15,2007.18-19and RGM 541.514-515,RGM518-519. Four concretions, withc. 37specimens, leg. O. Barsoe Hansen, 2007 (OB931, OB982,OB 1127,OB 1199, OB 1214). Nrs OB868,OB 881 andOB 931 alsocontain specimens ofHeliconoidesmercinensis,nr.OB 1072also containsthesingle specimen ofLimacina? pygmaea; siliconecasts in ISL2007.16-17,2007.20-21, 2007.23 and RGM 541.516-517,RGM 541.520-522). One concretion with c. 20 specimens, O. Barsee Hansen,2007 (OB 1203), siliconecasts in ISL2007.22andRGM 541.523. From thisconcre- tion asampleof c. 12gwas isolatedfor dinoflagellate cyst study. ]anssenetal:Pteropods from theEoceneLillebaeltClay Formation(Denmark,Jylland) 163 Fig. 13.Silicone latexcast ofpartofconcretion OB Fig. 12. Concretion OB 229 containing external 229,RGM541.508,original concretion(see fig. 12) moulds of the holotype and 13 paratypes of in MGUH 28735, leg./don. Ole Barsøe Hansen, Heliconoides lillebaeltensis sp. nov. Coll. MGUH 2004. Photograph courtesy of Sten Lennart 28735, leg./don. Ole Barsøe Hansen, 2004. Jakobsen, MGUH; a: holotype (see fig. 3), b-d: PhotographISL. paratypesillustrated figs4-6. Discussion. - Among the Eocene species describedfrom theNorthSea Basinonly Limacinanemoris Curry, 1965resemblesthepresentnewspecies. However,that species remains smaller, itsspirais moreelevated,theapertureis moreroundedand thereare noaperturalreinforcements. None of the species described from theYpresian of SW Franceby Curry (1982) demonstratessimilaritywithHeliconoideslillebaeltensis.Fromspecies recordedfromthe Eocene of the United Statesby Hodgkinson et al.(1992) only .H. stenzeli (Garvie, in Hodgkinson etal., 1992) resembles thenew species, but itis distinctlymore slender, withthewhorlsattaching atorbelowtheperiphery, and itsaperturereaches only half theshellheight. Alsoitsaperturalmargin seemstobe differentlyshapedandthickened internally. Distribution.- Heliconoideslillebaeltensisspec. nov. is exclusively known from its typelocality. Heliconoidesmercinensis (Watelet& Lefèvre, 1885)(figs 7, 8) Planorbis ikke uligPl. vortex menmaaske enValvatina - Morch,1874:279. Spirialismercinensis Watelet&Lefevre, 1885:102,pi. 5fig. 2a c;Korobkov, 1966: 73,77,78. ? ValvatinamercinensisWatelet etLefevre;Dollfus&Ramond,1886:42. ? Valvatina merciniensis (sic)Wat.etLef.;Cossmann,1892:9;Cossmann,1896:93. Valvatina raphistomaStolley,1900:12,figsla-c,2;Ravn, 1907:368;Hucke &Voigt, 1967:99,104,pi.45fig.1 Valvatina merciniensis(sic)(Wat.etLef.);Cossmann &Pissarro, 1913,expl. pi.60,nr.Pteropodes2-2. SolariumorHomolaxis,juvenile;Wrigley, 1924: 255 ? Valvatina spec.;Davis & Elliott,1951:337. Spiratella mercinensis (WateletetLefevre,1880);Glibert,1962:61;Curry,1965:366,figs15a-b,16;Cooper &Rundle,1969: 191;Rundle &Cooper, 1970: 116,118;James,Ward&Cooper,1974:55;King& King, 1976:23;George& Vincent,1977:85,86; Bristow,Ellison& Wood, 1980:266,fig. 3;King, 1981:124,125,131,figs44,45;Bemasconi&Robba,1982:213;King,1984:142,143,fig. 10;Cooper, 1984:8. 164 BASTERIA,Vol. 71, No. 4-6, 2007 ? Valvatina spec. - Venables,1963:262. Limacina mercinensis (Watelet&Lefevre, 1885);Janssen&King,1988;Janssen, 1990:65;Zorn,1991:11,12; Natural HistoryMuseum website,2007, fig. LimacinaplanidorsalisHodgkinson;Hodgkinsonetal., 1992:19,pi.3figs 11-13(?). Heliconoides mercinensis (Watelet&Lefevre, 1880);Janssen,2007,website,fig. non:Spiratella mercinensis (Watelet&Lefevre);Curry, 1982: 36,pi.1fig. la-b(=Heliconoides spec. nov.?). Description. - Shell sinistral, planorboid, withapproximately 31/2roundedwhorls in a regular spiral. Initial whorlnot protruding, apical plane slightly concave. Aperture roundedinfrontalview,only very slightly highterthan penultimatewhorl.Thebasalpart oftheapertureisloweredbeyond thebaseoftheforegoing whorl.Aperturalmarginwith a rounded v-shaped incision (lateral view), internally thickened. Umbilicus wide and shallow. Materialexamined.- Two concretionswith respectively many and two specimens, leg./don. M. Madsen, 2000,colln MGUH, silicone casts in ISL 1999.56and 1999.58, and RGM 429.552, and 429.554. The concretion with many specimens also contains four paratypes ofHeliconoideslillebaeltensisspec.nov. Three concretions withfive specimens, leg./don. M. Madsen, 2006, colln MGUH, silicone casts in ISL2007.3-4and 2007.6and RGM 541.503-504, RGM 541.506. One concretion also contains eight specimens of Heliconoides lillebaeltensis spec. nov. One concretionwith c. 55 specimens, leg./don. M. Madsen,2006, colln RGM541.507,also containing ten specimens of Heliconoideslillebael- tensisspec,nov.;siliconecastin ISL2007.7. Two concretions withc.30and c.20specimens, leg.O. BarsoeHansen,2004(OB608,OB676)SiliconecastsinISL2007.10and2007.12,and RGM541.510and RGM541.512.Twoconcretions withfivespecimens leg./don. O.Barsoe Hansen,2007(OB868,OB881), collnMGUH;one specimen in OB 868 illustratedFig. 10 (MGUH28738); silicone casts in ISL2007.14-15and RGM541.514-515.Both concretions also containspecimens of Heliconoideslillebaeltensisspec. nov. Two concretions with one and c. 35 specimens, leg. O. BarsoeHansen, 2007(OB 931,OB 982); silicone casts in ISL 2007.16-17andRGM541.516-517); OB 931 alsocontains 8 specimens of Heliconoideslille- baeltensisspec. nov. Discussion. - Although quiteanumberof specimens arepresentintheavailablecon- cretionstheaperturalreinforcementsarenot visiblein anyof thesiliconelatexcasts.Still, thegeneral shapeis so typicalthat theidentificationcannot be doubted.Heliconoides mer- cinensiswas originally describedfromYpresian('Cuisian') depositsofMercin, ParisBasin (France, department of Aisne). The present specimens reach slightly larger dimensions thantheParisBasin shells(W =2.3mm, specimen illustratedhereinfig. 10). AccordingtoCurry(1965:366)thesix syntype specimens areabsentfromtheWatelet collection, housedin theMuseedeSoissons, France.Inthe original description nomen- tionis madeoftheapertural morphology, forwhichreason Curry(1965,fig. 16)illustrat- ed aspecimen fromtheSablesdeCuise atAizy-Jouy (just20km fromthe typelocality). His drawing demonstratesclearlythe v-shaped incisionoftheapertural margin,butnot the internalapertural ridge. We reproduce here some drawings (fig. 9a-d) of the same specimen (BMNH GG7117, leg. D.Curry) fromAizy-Jouy, in which thisfeature is clear- ly seen. Thetaxon Spirialis ‘subanguostus’Watelet& Lefevre (1885:102, fig.la-c), obviously a lapsusforS.subangulosus, asseen in theexplanation oftheirfig. 1,describedonthebasis of a single specimen (also not found in the Wateletcollection), from the same locality Mercin,was consideredbyCurry (1965)withsomedoubttobeasynonymof thepresent species. However, considering the shape of the aperture, as illustrated by Watelet& Lefevre, showing asubangular abaxialmarginneverseenin Heliconoidesmercinensis,this Janssen etal.:Pteropodsfrom theEoceneLillebaeltClay Formation(Denmark, Jylland) 165 seemsunlikely. Thechoiceofthename ‘subangulosus’indicatesthattheshapeoftheaper- tureis not only anunsuccessful drawing (unless, of course, the description was basedon the drawing !). Alsothe size(W =2.5mm) exceeds thatof H.mercinensisfrom theParis Basin.Dollfus& Ramond(1885: 39), bytheway misspelling thenameas Spirialis ‘suban- gulatus’, considered it a synonym of the freshwater gastropod Planorbis hemistoma Sowerby, 1815.Theoriginal description of P. hemistomain Sowerby (1815:91, pi. 140 fig. 6), however,is too shortandtheillustrationsaretoo smalltobecertain aboutthis. Limacinaplanidorsalis Hodgkinson (in Hodgkinson et al., 1992: 18, pi. 3 figs 11-13), fromEarlytoMiddleEoceneof someoff-shorewellsEofCanada,resemblesHeliconoides mercinensiscloselyand mightbeasynonym.Theapertural features,however,are notpre- servedinthetypespecimens. Distribution.- Thepresenceofthis species in sedimentsofEarly Lutetianageis sur- prising. Heliconoides mercinensis is the oldest pteropod species known. Apart from the Ypresian occurrences in the Paris Basin this species is also known from the earliest Ypresian of Denmark (Fur Formation, Mo Clay), from theLate Palaeocene(Tuscahoma SandFormation, BearCreek Marls)ofAlabama(USA), fromtheYpresian (LondonClay Formation) inEngland, fromtheYpresian (Paniseland Flandersformations) inBelgium, and fromsupposed Ypresian sedimentsin TheNetherlands(Opende borehole) (mostof thesecollnRGM). Specimens recorded from the Ypresian of Gan (Aquitaine Basin, France) by Curry (1982) belongto anotherspecies (seeJanssen& Cahuzac,in prep.). LimacinaBosc,1817 Typespecies:Limacina helicina (Phipps, 1774),bymonotypy(Recent). Limacinapygmaea(Lamarck, 1805)?(fig. 11) Ampullairepygmee,Ampullaria(pygmaea);Lamarck,1805:30. Ampullairepygmée,Ampullariapygmaea;Lamarck, 1806,pi.61. fig.6a-b. Spiratellapygmaea (Lamarck)1804;Curry, 1965:362,figs 18a-b,19(withfurthersynonymy). Description. - Asingle,poorly preserved specimen has avery lowspira, considerably lowerthanallspecimens oftheaccompanying species Heliconoideslillebaeltensisspec,nov., and mightbelong tothiswell-knownLutetianspecies. Itsapertural featuresare not visi- ble. Materialexamined.-Onespecimen fromthetypelocality ofHeliconoideslillebaeltensis spec, nov.,co-occurring with15specimens ofthatspecies inconcretion OB 1072,leg./don. O. Barsoe Hansen, 2007, colln MGUH 28739; silicone casts in ISL 2007.19 and RGM 541.519. Distribution.- Eocene (Lutetian) of theParis and NorthSea basins. Also recorded (Curry, 1982) fromthe Ypresian of Gan (Aquitaine Basin) and from the MiddleEocene (Bartonian) of Texas (USA). The illustrations, however, of the latter occurrence in Hodgkinson etal.(1992, pi. 3figs 14, 15) representanotherspecies. Spiratellapseudopyg- maeaEames(1952: 150,pi.6 fig. 146a-b),basedonjuvenile specimens fromtheEoceneof India/Pakistan, mightberelatedor evenidentical. 166 BASTERIA,Vol. 71, No.4-6,2007 BIOSTRATIGRAPHICALNOTES (A.W.Janssen) Thepteropod assemblage found intheTreldeNaes concretionsyielded two common pteropod species, and asingle doubtfulspecimen of athird species. Themostabundant species,Heliconoides mercinensis, is an extremely commonspecies in several deposits of Late Palaeocene to Early Eocene (Ypresian) age and is also known from Cuisian (= Ypresian) sedimentsintheParisBasin. Janssen&King(1988)recordedoccurrences ofthis species in pteropod zones 6 to 9, covering a LatePalaeocene-Ypresian age. Thepresent study includes a reliable age assignment of the concretions as Early Lutetian, which extendstherangeofH. mercinensisupwards, asthe species hadnotbeenfoundinMiddle Eocene deposits so far. Thefact thatthenewspeciesHeliconoideslillebaeltensisis commoninthepresent sam- ples,and co-occurs withH. mercinensis inanumberofconcretions, is striking. Itindicates thatina(mayberelatively short) Eoceneintervalthespecies occurred quiteabundantly in theNorthSeaBasin.Still, intheUK,inDenmarkandTheNetherlands,wherepteropods fromtheEoceneare well-studied, thespecies hasneverbeenfoundso far.Mostprobably theoccurrences havetobeincludedinthebasalpartofPteropod Zone9ofJanssen& King (1988), butother species known fromthisinterval, such asLimacinataylori(Curry, 1965), L.tutelina(Curry, 1965),Euchilothecasuccincta(Defrance, 1828)and/orCamptoceratops prisca (Godwin-Austen, 1882),were not found. ACKNOWLEDGEMENTS Theauthorsare especially grateful toMessrs Mogens Madsen (Fredericia,Denmark) andOleBarsoeHansen (Kolding, Denmark) for donating materialand forpermission to studyspecimens intheircollections.MrStenLennartJakobsen(MGUH)was kindenough tomakethephotograph of fig. 13. Thefirstauthoris grateful to MessrsMogens Madsen andIngemann Schnetler, formakingall siliconelatexcastsand donating asetoftheseto theRGM collections.Dr Crispin Little(School of Earth and Environment,University of Leeds,UK)criticallyreadthemanuscript andimproved theEnglish. REFERENCES BERNASCONI, M.R, & E. ROBBA, 1982. Thethecosomatous pteropods: a contribution towards the Cenozoic Tethyanpaleobiogeography.- Bollettino della SocietaPaleontologicaItaliana 21: 211-222. BONDE, N. (1968):Nyligt fundne fossiler fra det"plastiske ler". - Meddelelser fraDansk Geologisk Forening18:148-151. BRISTOW, C.R.,R.A. ELLISON & C.J. WOOD, 1980. TheClaygateBeds ofEssex.-Proceedings ofthe Geologists'Association91:261-277. COLLINS, J.H.S. & S.L. JAKOBSEN, 2003. New crabs (Crustacea, Decapods) from the Eocene (Ypresian/Lutetian)Lillebaelt ClayFormation ofJutland,Denmark.- Bulletin oftheMizunamiFossil Museum30:63-96. COOPER, J., 1984. 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