GEOLOGICA BALCANICA, 24, 5, Sofia, Oct. 1994, p. li-4G Dinoflagellate cysts from the Bathonian - Tithonian (Jurassic) of North Bulgaria. III. Tithonian dinoflagellate cysts Lilia Dodekova Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia (Received 14 . Ofi. 1994; accrpted 1fi. 06. 1991) JJ. JloileKoaa - Lf.ucmht iJuHotp,zai!eAAam 6ama - mumoHa ( 10pa) a Ceoe pHoii DOAi!apuu . Ill. TaKco­ ltOAtUJ! /llU/IlOHCKIIX !{UC/Il UUHOt/JAazeAAam. J1cc,1e)lOBaHbl )lHIWUHCTbl THTOI!CKHX MOpCKHX OTJ!Oll<eHHI1 00 pa3pe3aM 34 IIe4JT51HbiX CKBalKHH H O,liHO eCTeCTBeiiOe 06I·Ia>KefiHe. 06HapylKCiibl 6oraTble II '13CTO XOpOWO COXpaHHBWIICCH KO ~ Jn JieKCbl JlHHOUHCT . 8 CT3Tbe Jtaiii>I KOpOTKHe CBe,lleHHH 0 MOfHjJOJ!Oriii!, T3KCOHOMHH, reorpa4JHlJCCKOM H CTp3THfpa4JH'leCK0~1 pacnpOCTp aiieHHH 56 T3K CO IIOIJ JlHIIOUHCT H 2 BH· JlOB aKpHrapx. Bee OHH noHBJ151IOTC51 B THTOHCKOM Hpyce . H OBble TaKCOHbl OriHCaHH bie 6oJJee )leTaJlbHO BKJJIO<JaiOT: Semicauidinium gen . n., S. mitra (D ii r r) comb. n., Amphorula monteiliae sp. n ., Cassi­ culosphaeridia cribrosa sp. n ., Kallosplweridium callosum sp. n ., Prolixosphaeridium? foratum sp . n ., Prolixosphaeridittm perforospineum sp. n ., Sentusidinium spatiosum sp. n ., Systematophora jubifera sp. n., Systematophora? prodigiosa sp. n., Pareodinia pauca sp . n. , Gonyaulacysta vesicula sp. n ., Lep­ todinium? ambiguiformis sp. n ., Leptodinium? plagatam sp . n., Pyxidinopsis? retiolum sp. n. YKa3auo crparHrpacjJH'IeCK oe pacnpocrpaHeHHe B DOJJrapHH ynmHIHYTI>IX AHHOUHCT ll ~tecrc c nepeXOJlHbniH raKCoHaMH . Ouu ycraHOBJleHHbl B II JJHrocrpaTHrpacjJH<JeCKIIX CJlHHHUax . :=ITo uccJJeJlOIJa iiiie }lonoJJ­ HHeT H03113IIHC KOM HJleKCOil JlHIIOUHCT TeTHCa ll KOHUe IOfJI.ol H 113 rpaHIIUe !Op a - ~teJJa. Abstract. Tithonian marine sediments from 34 boreholes and one outcrop in North Bulgaria have been palynologically examined. They contain rich and commonl y well preservect dinocyst assemblages. This paper includs brief comments on morphology , taxonomy, geographi c and stra­ tigraphic distribution of 56 dinocyst taxa and 2 acritarch species which start in this se quence. The new of them are sketched and described in detail. They include: Semicauidinium gen. n ., S. mitra (D ii r r) comb. n ., Amphora/a monteiliae sp . n., Cassiculosphaeridia cribrosa sp. n., Kallosphaeri­ dium ca llosum sp, n., Prolixosphaeridium? fora tum sp. n., Prolixosphaeridium perforospineum sp . n., Sentusidinium spaliosum sp. n ., Systematophora jubifera sp. n., Systematophora? prodigiosa sp . n., Pareodinia pauca sp. n ., Gonyaulacysta vesicula sp. n., Leptodinium? ambiguiformis sp.n., Leptodi­ nium? plogatum sp. n., Pyxidinopsis? retiolum sp . n. On a range chart the stratigraphic distribution of mentioned taxa together with transitional clinocyst species is summarized. They were found in II I ithostra tigraphic units. This rese<~rch suppl emen t s the knowledge of the true T ethyan assem bl a gcs in Late .Jurassic and Jurass ic - Cretaceous boundary. Introduction The present paper is the third in a series of four articles dealing with the Jurassic di­ nocysts of Nort h Bulgaria. It summarizes palynological data accumulated over many years from study on 34 boreholes and one outcrop (Fig. 1). In North Bulgaria the Jurassic marine sequence is essentially continous and per­ mits to establish a full dinocyst succession. The present study indicates that the diffe- II R 0 M A N r A 0 BELOGRADC IK •1 PLEVEN 0 •10 •11-15 16 •19 OLOVEC. •ZO OSEVl-.IEVO •21 Fig. I. Location of the studied boreholes and outcrop with Tithonian sediments: 1- R-2 Milcina !aka, 2-R-3 Komostica, 3-R-1 Hajredin, 4-R-1 Bardarski geran, 5- Beglez, 11-R-2 Devetaki, 12-R-3 Devetaki, 13-R-4 Devetaki, 14-R-5 Devetaki, 15- 20- R-1 Suhindol, 21- Mahala Porska, 22- R-1 Kav1ak, 23- S-1 Razgrad, 24- S-24 Sultanci, 29- R-11 Zitnica, 30- R-IO Padina, 31- R-1 Junak, 32- R-3 Junak, 33- rent I ithostratigraphic units related to the Tithonian contain a large number of dino­ cysts. Most of them have restricted vertical and extensive horizontal distribution. Thus they facilitate detailed stratigraphic subdivision ·and correlation. The results of these investigations dealing main! y with the stratirgaphy have been pub! ished by .Uo ;teKOBa in CanyHOB eta!., 1986a, CanyHOB eta!., 1986b, Cany­ H o B, 4 y M a q e H K o, 1987. In these papers the main lithostratigraphic units were shown as well as all records of ammonites, calpionellids and some importante dinocyst species. In the world the dinocyst assemblages from the Tethyan Region are not enough investigated in comparison with those of the Boreal Province. For that reason, there are much new taxa in these assemblages which are significant for Tithonian strati­ graphy and the Jurassic -Cretaceous boundary. Some of them have been published by Dod e k ova (1969). In this paper they are refigured. The model of the text, the used terminology, construction of the range-chart and method of work are discussed in the first article (D o d e k o v a, 1990) and partly in the second paper (Do cl e k ova, 1992). The biostratigraphic analysis of the dinocysts from the Tithonian sediments of North Bulgaria (Fig. 2) is controlled by the independent studies of ammonites and calpionellids. The standard ammonite zonation and chronostratigraphic units in this country have been established by Sap uno v (1977), Can y H oR (1979), N i k o- 1 o v, Sap uno v (1977) and the calpionellid zonal scheme respectively by B aka- 1 ova (1977) and B aka I o v n in N i k o I o v, Sap uno v (1977). A strati- 12 23 OTOLBUHIN -oRAZGRAD OPROVADIJA 26-~:[ •Jl •25 32.•34 R-1 Kneza, 6- R-l Dolni .Dabnik, 7-R-1 Trastenik, 8-R-1 Gigen, 9- R-l Brest. 10 - R-2 R-8Devetaki , 16-R-1 Brestovo, 17-R-1 Stezerovo, 18 - R-l Svistov, 19-R-1 Karpacevo, Nikola Kozlevo, 25- R-9 Bozvelijsko, 26- R-6 Sultanci, 27- R-7 Sultanci, 28- R-8 R-4 Junak, 34- R-14 Grozdjovo, 35- R-1 Georgi Trajkov graphic scheme of the stages. substuges. the ammonite and calpionellicl zones and subzones is shown on Fig 3. The litostratigraphic unit used in this paper are revised by C a n y 11 o B, 4 y M a 4 e H '' o (1986). All dinocyst species studied and figured here are being kept in the collections of the Geological Institute, Bulgarian Academy of Sciences. Aclmowledwmcnts. I would l i kc to express my sincerest thanks tu my foreign cull cagues pal ynulo­ gisls. They arc grateful ly acknowledged fur sending i mpurtant literature on dinocysts and fur their competent suggestions and criticisms, special ly tu Dr W. A. S. Sarjeant. My thanks to L. Zafirova and E. Tomova for processing the palynological sa mples, S. Antonova and L. Panova for printing the photographs and Z. Mishova for drawing the tex t-figures. l am grateful to the Geological Institute for supporting me during my research. Taxonomv Dinocysts with apical archeopyle Genus Amphorula -Dod e k o v a, 1969 emend. Z otto et al., 1987 emend . M o n t e i I, 1990 Type s p e c i e s (by original designation): Amphorula metaelliptica Do cl e k o­ v a, 1969 . 13 ~---- ----------- -----------·------------------- -r----------------------- LATE JUI~ASSIC TITHONIAN AGE m )> r IJ 0 )>_, r 0 DINOFLAGELLATE -< r m CYSTS m 1 2 ·1 1. Eilipsoitlictyum cinctum ----·· 2. Rignutlclla filamcnto8a r-·---- 3. rJcf.;fOSJ1hR,.rit/ium pofyfrirhwu ~ ----- ·1. ,1t/nato.-;pbnrritlium caul/crJ'i ~- ­ 5. Sr.ntw;idinium rioultii !4--· fi. Ew:harispbarritlia pococ.kii 7. Scriniotlinium galcritum galcritum 8. Rbyncbotliniopsis clntlopbora 9. Po~ygonifcra baJ·o.rica 10. Litbotlinia hcjuii 11. Systcmstopbora arcolata 12. l!..'piplospbaera arcolata + --- --------- 13. Epiplospbaera hireticulata H. Xcnicotlinium tlcnsispinosum 15. His fiophora ornata 16. Cribroperitiinium? globatum 17. Egmonlotlini11m po~vplacopborum Ut Gochtcotlinia ruutahilis 19. Prri.... w :in!ipbnrritlium d. ingcgrrtlii 20. Subli/ir;phnrrn p11cmino8R 21. l':dc-n:,irlln m·uln Z2. Cbyt ror-i-;piJacritlia t•hyt roritlrs 2:~. ,·1rantbau/ax 1-(THIIUfi!{rT/1 2i. IA"plotlinium suhli!f· 2.5. /Jinoptcrigium rlinwrphum 14-------;---- - Z6. llJ•strirho.<iph:u:rin:I orbifrn1 !7. Ampborula tlotlrkovac !8. Epiplospbacra rcticu/ospi11osa 29. 1/ys tric.bo.<;p.bnuina crusta 30. Acantbaulax Vt>nusta 31. Atlantotlinium· jurassicuru 3!. Hr;;trichosphaerilla sp. aff. ll -'>llrjt·antii 33. Lanterns cruiteda 3-i. l!..,l{mnntotlinium t'XJ1ir11tum 35. Scnlusidiniwu spatin:,um 36. Pyxitli11opsis ? retiolwu _._ ~ '------- - ------- --··- ·----------- -- · ----------~-· · - _. ___ _____ 14 1 2 3 4 37 . .Ril(ltudl'lln tll'I!mln 38. ,O.,'cril•iodiuium didyotum dictyotum 39. 8yslrrunlt1plwrn penirilni1J ~ ·- ·10. Prolixospbacridiwu mi:"ti:,.pillo .~ wll ----·· -- -- 11. Tt•barundiuiuru nrulr.nluru ~ ------ - 12. Scriuiodiuiwu plnyfortlii 13. Lcptotliniwn'! clntbnJtum ·- - 44. Leptodinium'! m aruillifrrum 0 -15. Arupborula mctaclliptica 46. Cassiculm•pbneritlin sp. 17. Cn.<;siculospbal'ritlia? crihros 11 -18. Cblam.vdopborclla s p. aff. C D,J'l'i •19. JJingodinium? tuheros um aO. Pandndinium spino.mm ~1. .Rl'IIIlingia gochtii ~2. P11rcodini11 <'t•ratophora ~--- ------- ·· ---- ~3 . ."iirmio.tl!niur_u !(ro.ssi - ··-r-----.,. 51 . .1-lcantbaulax granulata ·-- ----· 55. Dingodinium jurassirum 56. Tuhotuherclla a pate/a 0 57. Dichadogonyaulax? pllUJlca 58. Dingotlinium alhr.riii -------- -~ 59. Prolixospbacridiurn hnsifurcnium 60. Tenua bystrix 61. Lantcrnn hulgt~ricn 62. Tcbamatlinium e~ ·itlii ij'l.,. Nummus .simi/is 61. Utl1odinin hu/Joidt·a 65. ( h·r.i.,·ucysla l111lio.,· 66. 8y.•dcm11topbora da n·,r 67 . ....:p; trmulopborn? prmligiosa 6X . A nu11lw u}u;" '! S JI . , \ 69. Lt•ptmlinium tiiJiiguuium 711 . l'llrrtulinill !liiUO I 71. l'rri.-; ..;t•ia .o;p/wcritliu m p11u1w.•:um 72. ,.,)·.o;tt·nwtophora Jubil(·r;J 73. , lmphorula drliml:1 ... 71. Cirnrlodiniuru c·ornpl<l 7:-i. { 'nnlt'lotlinir:m huhihii 76. I lif'b:ulo;;ony ll uh1x st·biLoillllln 77.